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      1 /* $NetBSD: ckgetopt.c,v 1.29 2026/01/10 17:12:26 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 (at) 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 #if defined(__RCSID)
     38 __RCSID("$NetBSD: ckgetopt.c,v 1.29 2026/01/10 17:12:26 rillig Exp $");
     39 #endif
     40 
     41 #include <stdbool.h>
     42 #include <stdlib.h>
     43 #include <string.h>
     44 
     45 #include "lint1.h"
     46 
     47 /*
     48  * In a typical while loop for parsing getopt options, ensure that each
     49  * option from the options string is handled, and that each handled option
     50  * is listed in the options string.
     51  */
     52 
     53 static struct {
     54 	/*-
     55 	 * 0	means outside a while loop with a getopt call.
     56 	 * 1	means directly inside a while loop with a getopt call.
     57 	 * > 1	means in a nested while loop; this is used for finishing the
     58 	 *	check at the correct point.
     59 	 */
     60 	int while_level;
     61 
     62 	/*
     63 	 * The options string from the getopt call.  Whenever an option is
     64 	 * handled by a case label, it is set to ' '.  In the end, only ' ' and
     65 	 * ':' should remain.
     66 	 */
     67 	pos_t options_pos;
     68 	int options_lwarn;
     69 	char *options;
     70 	char *remaining;
     71 
     72 	/*
     73 	 * The nesting level of switch statements, is only modified if
     74 	 * while_level > 0.  Only the case labels at switch_level == 1 are
     75 	 * relevant, all nested case labels are ignored.
     76 	 */
     77 	int switch_level;
     78 } ck;
     79 
     80 /* Return whether tn has the form '(c = getopt(argc, argv, "str")) != -1'. */
     81 static bool
     82 is_getopt_condition(const tnode_t *tn, char **out_options)
     83 {
     84 	const function_call *call;
     85 	const tnode_t *last_arg;
     86 	const buffer *str;
     87 
     88 	if (tn != NULL
     89 	    && tn->tn_op == NE
     90 
     91 	    && tn->u.ops.right->tn_op == CON
     92 	    && tn->u.ops.right->u.value.v_tspec == INT
     93 	    && tn->u.ops.right->u.value.u.integer == -1
     94 
     95 	    && tn->u.ops.left->tn_op == ASSIGN
     96 	    && tn->u.ops.left->u.ops.right->tn_op == CALL
     97 	    && (call = tn->u.ops.left->u.ops.right->u.call)->func->tn_op == ADDR
     98 	    && call->func->u.ops.left->tn_op == NAME
     99 	    && strcmp(call->func->u.ops.left->u.sym->s_name, "getopt") == 0
    100 	    && call->args_len == 3
    101 	    && (last_arg = call->args[2]) != NULL
    102 	    && last_arg->tn_op == CVT
    103 	    && last_arg->u.ops.left->tn_op == ADDR
    104 	    && last_arg->u.ops.left->u.ops.left->tn_op == STRING
    105 	    && (str = last_arg->u.ops.left->u.ops.left->u.str_literals)->data != NULL) {
    106 		buffer buf;
    107 		buf_init(&buf);
    108 		quoted_iterator it = { .end = 0 };
    109 		while (quoted_next(str, &it))
    110 			buf_add_char(&buf, (char)it.value);
    111 		*out_options = buf.data;
    112 		return true;
    113 	}
    114 	return false;
    115 }
    116 
    117 static void
    118 check_unlisted_option(char opt)
    119 {
    120 	if (opt == ':' && ck.options[0] != ':')
    121 		goto warn;
    122 
    123 	const char *optptr = strchr(ck.options, opt);
    124 	if (optptr != NULL)
    125 		ck.remaining[optptr - ck.options] = ' ';
    126 	else if (opt != '?')
    127 	warn:
    128 		/* option '%c' should be listed in the options string */
    129 		warning(339, opt);
    130 }
    131 
    132 static void
    133 check_unhandled_option(void)
    134 {
    135 	for (const char *opt = ck.remaining; *opt != '\0'; opt++) {
    136 		if (*opt == ' ' || *opt == ':')
    137 			continue;
    138 
    139 		int prev_lwarn = lwarn;
    140 		lwarn = ck.options_lwarn;
    141 		/* option '%c' should be handled in the switch */
    142 		warning_at(338, &ck.options_pos, *opt);
    143 		lwarn = prev_lwarn;
    144 	}
    145 }
    146 
    147 
    148 void
    149 check_getopt_begin_while(const tnode_t *tn)
    150 {
    151 	if (ck.while_level == 0) {
    152 		if (!is_getopt_condition(tn, &ck.options))
    153 			return;
    154 		ck.options_lwarn = lwarn;
    155 		ck.options_pos = curr_pos;
    156 		ck.remaining = xstrdup(ck.options);
    157 	}
    158 	ck.while_level++;
    159 }
    160 
    161 void
    162 check_getopt_begin_switch(void)
    163 {
    164 	if (ck.while_level > 0)
    165 		ck.switch_level++;
    166 }
    167 
    168 void
    169 check_getopt_case_label(int64_t value)
    170 {
    171 	if (ck.switch_level == 1 && value == (char)value)
    172 		check_unlisted_option((char)value);
    173 }
    174 
    175 void
    176 check_getopt_end_switch(void)
    177 {
    178 	if (ck.switch_level == 0)
    179 		return;
    180 
    181 	ck.switch_level--;
    182 	if (ck.switch_level == 0)
    183 		check_unhandled_option();
    184 }
    185 
    186 void
    187 check_getopt_end_while(void)
    188 {
    189 	if (ck.while_level == 0)
    190 		return;
    191 
    192 	ck.while_level--;
    193 	if (ck.while_level != 0)
    194 		return;
    195 
    196 	free(ck.options);
    197 	ck.options = NULL;
    198 	free(ck.remaining);
    199 	ck.remaining = NULL;
    200 }
    201