1 /* $NetBSD: ckbool.c,v 1.29 2024/02/03 12:57:12 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: ckbool.c,v 1.29 2024/02/03 12:57:12 rillig Exp $"); 40 #endif 41 42 #include <string.h> 43 44 #include "lint1.h" 45 46 47 /* 48 * The option -T treats _Bool as incompatible with all other scalar types. 49 * See d_c99_bool_strict.c for the detailed rules and for examples. 50 */ 51 52 53 /* 54 * See if in strict bool mode, the operator takes either two bool operands 55 * or two arbitrary other operands. 56 */ 57 static bool 58 is_assignment_bool_or_other(op_t op) 59 { 60 return op == ASSIGN || 61 op == ANDASS || op == XORASS || op == ORASS || 62 op == RETURN || op == INIT || op == FARG; 63 } 64 65 static bool 66 is_symmetric_bool_or_other(op_t op) 67 { 68 return op == EQ || op == NE || 69 op == BITAND || op == BITXOR || op == BITOR || 70 op == COLON; 71 } 72 73 static bool 74 is_int_constant_zero(const tnode_t *tn, tspec_t t) 75 { 76 return t == INT && tn->tn_op == CON && tn->tn_val.u.integer == 0; 77 } 78 79 static bool 80 is_typeok_strict_bool_binary(op_t op, 81 const tnode_t *ln, tspec_t lt, 82 const tnode_t *rn, tspec_t rt) 83 { 84 if ((lt == BOOL) == (rt == BOOL)) 85 return true; 86 87 if (op == FARG && rn->tn_sys) 88 return false; 89 90 if ((ln->tn_sys || rn->tn_sys) && 91 (is_int_constant_zero(ln, lt) || is_int_constant_zero(rn, rt))) 92 return true; 93 94 if (is_assignment_bool_or_other(op)) 95 return lt != BOOL && (ln->tn_sys || rn->tn_sys); 96 97 return !is_symmetric_bool_or_other(op); 98 } 99 100 /* 101 * Some operators require that either both operands are bool or both are 102 * scalar. 103 * 104 * Code that passes this check can be compiled in a pre-C99 environment that 105 * doesn't implement the special rule C99 6.3.1.2, without silent change in 106 * behavior. 107 */ 108 static bool 109 typeok_strict_bool_binary_compatible(op_t op, int arg, 110 const tnode_t *ln, tspec_t lt, 111 const tnode_t *rn, tspec_t rt) 112 { 113 if (is_typeok_strict_bool_binary(op, ln, lt, rn, rt)) 114 return true; 115 116 if (op == FARG) 117 /* parameter %d expects '%s', gets passed '%s' */ 118 error(334, arg, tspec_name(lt), tspec_name(rt)); 119 else if (op == RETURN) 120 /* function has return type '%s' but returns '%s' */ 121 error(211, tspec_name(lt), tspec_name(rt)); 122 else 123 /* operands of '%s' have incompatible types '%s' and '%s' */ 124 error(107, op_name(op), tspec_name(lt), tspec_name(rt)); 125 126 return false; 127 } 128 129 /* 130 * In strict bool mode, check whether the types of the operands match the 131 * operator. 132 */ 133 bool 134 typeok_scalar_strict_bool(op_t op, const mod_t *mp, int arg, 135 const tnode_t *ln, 136 const tnode_t *rn) 137 { 138 ln = before_conversion(ln); 139 tspec_t lt = ln->tn_type->t_tspec; 140 tspec_t rt = NO_TSPEC; 141 if (rn != NULL) { 142 rn = before_conversion(rn); 143 rt = rn->tn_type->t_tspec; 144 } 145 146 if (rn != NULL && 147 !typeok_strict_bool_binary_compatible(op, arg, ln, lt, rn, rt)) 148 return false; 149 150 if (mp->m_compares_with_zero) { 151 bool binary = mp->m_binary; 152 bool lbool = is_typeok_bool_compares_with_zero(ln); 153 bool ok = true; 154 155 if (!binary && !lbool) { 156 /* operand of '%s' must be bool, not '%s' */ 157 error(330, op_name(op), tspec_name(lt)); 158 ok = false; 159 } 160 if (binary && !lbool) { 161 /* left operand of '%s' must be bool, not '%s' */ 162 error(331, op_name(op), tspec_name(lt)); 163 ok = false; 164 } 165 if (binary && op != QUEST && 166 !is_typeok_bool_compares_with_zero(rn)) { 167 /* right operand of '%s' must be bool, not '%s' */ 168 error(332, op_name(op), tspec_name(rt)); 169 ok = false; 170 } 171 return ok; 172 } 173 174 if (!mp->m_takes_bool) { 175 bool binary = mp->m_binary; 176 bool lbool = lt == BOOL; 177 bool ok = true; 178 179 if (!binary && lbool) { 180 /* operand of '%s' must not be bool */ 181 error(335, op_name(op)); 182 ok = false; 183 } 184 if (binary && lbool) { 185 /* left operand of '%s' must not be bool */ 186 error(336, op_name(op)); 187 ok = false; 188 } 189 if (binary && rt == BOOL) { 190 /* right operand of '%s' must not be bool */ 191 error(337, op_name(op)); 192 ok = false; 193 } 194 return ok; 195 } 196 197 return true; 198 } 199 200 bool 201 is_typeok_bool_compares_with_zero(const tnode_t *tn) 202 { 203 while (tn->tn_op == COMMA) 204 tn = tn->tn_right; 205 tn = before_conversion(tn); 206 207 return tn->tn_type->t_tspec == BOOL 208 || tn->tn_op == BITAND 209 || (tn->tn_sys && is_scalar(tn->tn_type->t_tspec)); 210 } 211 212 bool 213 fallback_symbol_strict_bool(sym_t *sym) 214 { 215 if (strcmp(sym->s_name, "__lint_false") == 0) { 216 sym->s_scl = BOOL_CONST; 217 sym->s_type = gettyp(BOOL); 218 sym->u.s_bool_constant = false; 219 return true; 220 } 221 222 if (strcmp(sym->s_name, "__lint_true") == 0) { 223 sym->s_scl = BOOL_CONST; 224 sym->s_type = gettyp(BOOL); 225 sym->u.s_bool_constant = true; 226 return true; 227 } 228 229 return false; 230 } 231