1 /* $NetBSD: ckbool.c,v 1.1 2021/04/06 13:17:04 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) && !defined(lint) 39 __RCSID("$NetBSD: ckbool.c,v 1.1 2021/04/06 13:17:04 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 exact rules and for examples. 50 */ 51 52 static const char * 53 op_name(op_t op) 54 { 55 return modtab[op].m_name; 56 } 57 58 /* 59 * See if in strict bool mode, the operator takes either two bool operands 60 * or two arbitrary other operands. 61 */ 62 static bool 63 is_assignment_bool_or_other(op_t op) 64 { 65 return op == ASSIGN || 66 op == ANDASS || op == XORASS || op == ORASS || 67 op == RETURN || op == INIT || op == FARG; 68 } 69 70 static bool 71 is_symmetric_bool_or_other(op_t op) 72 { 73 return op == EQ || op == NE || 74 op == BITAND || op == BITXOR || op == BITOR || 75 op == COLON; 76 } 77 78 static bool 79 is_int_constant_zero(const tnode_t *tn, tspec_t t) 80 { 81 return t == INT && tn->tn_op == CON && tn->tn_val->v_quad == 0; 82 } 83 84 static bool 85 is_typeok_strict_bool(op_t op, 86 const tnode_t *ln, tspec_t lt, 87 const tnode_t *rn, tspec_t rt) 88 { 89 if (rn == NULL) 90 return true; /* TODO: check unary operators as well. */ 91 92 if ((lt == BOOL) == (rt == BOOL)) 93 return true; 94 95 if ((ln->tn_from_system_header || rn->tn_from_system_header) && 96 (is_int_constant_zero(ln, lt) || is_int_constant_zero(rn, rt))) 97 return true; 98 99 if (is_assignment_bool_or_other(op)) { 100 return lt != BOOL && 101 (ln->tn_from_system_header || rn->tn_from_system_header); 102 } 103 104 return !is_symmetric_bool_or_other(op); 105 } 106 107 /* 108 * Some operators require that either both operands are bool or both are 109 * scalar. 110 * 111 * Code that passes this check can be compiled in a pre-C99 environment that 112 * doesn't implement the special rule C99 6.3.1.2, without silent change in 113 * behavior. 114 */ 115 static bool 116 typeok_strict_bool_compatible(op_t op, int arg, 117 const tnode_t *ln, tspec_t lt, 118 const tnode_t *rn, tspec_t rt) 119 { 120 121 if (is_typeok_strict_bool(op, ln, lt, rn, rt)) 122 return true; 123 124 if (op == FARG) { 125 /* argument #%d expects '%s', gets passed '%s' */ 126 error(334, arg, tspec_name(lt), tspec_name(rt)); 127 } else if (op == RETURN) { 128 /* return value type mismatch (%s) and (%s) */ 129 error(211, tspec_name(lt), tspec_name(rt)); 130 } else { 131 /* operands of '%s' have incompatible types (%s != %s) */ 132 error(107, op_name(op), tspec_name(lt), tspec_name(rt)); 133 } 134 135 return false; 136 } 137 138 /* 139 * In strict bool mode, check whether the types of the operands match the 140 * operator. 141 */ 142 bool 143 typeok_scalar_strict_bool(op_t op, const mod_t *mp, int arg, 144 const tnode_t *ln, 145 const tnode_t *rn) 146 147 { 148 tspec_t lt, rt; 149 150 ln = before_conversion(ln); 151 lt = ln->tn_type->t_tspec; 152 153 if (rn != NULL) { 154 rn = before_conversion(rn); 155 rt = rn->tn_type->t_tspec; 156 } else { 157 rt = NOTSPEC; 158 } 159 160 if (!typeok_strict_bool_compatible(op, arg, ln, lt, rn, rt)) 161 return false; 162 163 if (mp->m_requires_bool || op == QUEST) { 164 bool binary = mp->m_binary; 165 bool lbool = is_typeok_bool_operand(ln); 166 bool ok = true; 167 168 if (!binary && !lbool) { 169 /* operand of '%s' must be bool, not '%s' */ 170 error(330, op_name(op), tspec_name(lt)); 171 ok = false; 172 } 173 if (binary && !lbool) { 174 /* left operand of '%s' must be bool, not '%s' */ 175 error(331, op_name(op), tspec_name(lt)); 176 ok = false; 177 } 178 if (binary && op != QUEST && !is_typeok_bool_operand(rn)) { 179 /* right operand of '%s' must be bool, not '%s' */ 180 error(332, op_name(op), tspec_name(rt)); 181 ok = false; 182 } 183 return ok; 184 } 185 186 if (!mp->m_takes_bool) { 187 bool binary = mp->m_binary; 188 bool lbool = ln->tn_type->t_tspec == BOOL; 189 bool ok = true; 190 191 if (!binary && lbool) { 192 /* operand of '%s' must not be bool */ 193 error(335, op_name(op)); 194 ok = false; 195 } 196 if (binary && lbool) { 197 /* left operand of '%s' must not be bool */ 198 error(336, op_name(op)); 199 ok = false; 200 } 201 if (binary && rn->tn_type->t_tspec == BOOL) { 202 /* right operand of '%s' must not be bool */ 203 error(337, op_name(op)); 204 ok = false; 205 } 206 return ok; 207 } 208 209 return true; 210 } 211 212 /* 213 * See if the node is valid as operand of an operator that compares its 214 * argument with 0. 215 */ 216 bool 217 is_typeok_bool_operand(const tnode_t *tn) 218 { 219 tspec_t t; 220 221 lint_assert(Tflag); 222 223 tn = before_conversion(tn); 224 t = tn->tn_type->t_tspec; 225 226 if (t == BOOL) 227 return true; 228 229 if (tn->tn_from_system_header && is_scalar(t)) 230 return true; 231 232 /* For enums that are used as bit sets, allow "flags & FLAG". */ 233 if (tn->tn_op == BITAND && 234 tn->tn_left->tn_op == CVT && 235 tn->tn_left->tn_type->t_tspec == INT && !tn->tn_left->tn_cast && 236 tn->tn_left->tn_left->tn_type->t_tspec == ENUM && 237 /* 238 * XXX: Somehow the type information got lost here. The type 239 * of the enum constant on the right-hand side should still be 240 * ENUM, but is INT. 241 */ 242 tn->tn_right->tn_type->t_tspec == INT) 243 return true; 244 245 return false; 246 } 247 248 bool 249 fallback_symbol_strict_bool(sym_t *sym) 250 { 251 if (Tflag && strcmp(sym->s_name, "__lint_false") == 0) { 252 sym->s_scl = CTCONST; /* close enough */ 253 sym->s_type = gettyp(BOOL); 254 sym->s_value.v_tspec = BOOL; 255 sym->s_value.v_ansiu = false; 256 sym->s_value.v_quad = 0; 257 return true; 258 } 259 260 if (Tflag && strcmp(sym->s_name, "__lint_true") == 0) { 261 sym->s_scl = CTCONST; /* close enough */ 262 sym->s_type = gettyp(BOOL); 263 sym->s_value.v_tspec = BOOL; 264 sym->s_value.v_ansiu = false; 265 sym->s_value.v_quad = 1; 266 return true; 267 } 268 269 return false; 270 } 271