xref: /netbsd-src/usr.bin/xlint/lint1/ckgetopt.c (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /* $NetBSD: ckgetopt.c,v 1.16 2022/05/20 21:18:55 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 #if defined(__RCSID)
38 __RCSID("$NetBSD: ckgetopt.c,v 1.16 2022/05/20 21:18:55 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 ' '
65 	 * and ':' should remain.
66 	 */
67 	pos_t options_pos;
68 	char *options;
69 
70 	/*
71 	 * The nesting level of switch statements, is only modified if
72 	 * while_level > 0.  Only the case labels at switch_level == 1 are
73 	 * relevant, all nested case labels are ignored.
74 	 */
75 	int switch_level;
76 } ck;
77 
78 #define NEED(cond) \
79 	do {				\
80 		if (!(cond))		\
81 			return false;	\
82 	} while (false)
83 
84 /* Return whether tn has the form 'getopt(argc, argv, "literal") != -1'. */
85 static bool
86 is_getopt_condition(const tnode_t *tn, char **out_options)
87 {
88 	const tnode_t *call, *last_arg;
89 
90 	NEED(tn != NULL);
91 	NEED(tn->tn_op == NE);
92 	NEED(tn->tn_left->tn_op == ASSIGN);
93 
94 	call = tn->tn_left->tn_right;
95 	NEED(call->tn_op == CALL);
96 	NEED(call->tn_left->tn_op == ADDR);
97 	NEED(call->tn_left->tn_left->tn_op == NAME);
98 	NEED(strcmp(call->tn_left->tn_left->tn_sym->s_name, "getopt") == 0);
99 
100 	NEED(call->tn_right->tn_op == PUSH);
101 
102 	last_arg = call->tn_right->tn_left;
103 	NEED(last_arg->tn_op == CVT);
104 	NEED(last_arg->tn_left->tn_op == ADDR);
105 	NEED(last_arg->tn_left->tn_left->tn_op == STRING);
106 	NEED(last_arg->tn_left->tn_left->tn_string->st_char);
107 
108 	*out_options = xstrdup(last_arg->tn_left->tn_left->tn_string->st_mem);
109 	return true;
110 }
111 
112 static void
113 check_unlisted_option(char opt)
114 {
115 	char *optptr;
116 
117 	lint_assert(ck.options != NULL);
118 
119 	if (opt == ':' && ck.options[0] != ':')
120 		goto warn;
121 
122 	optptr = strchr(ck.options, opt);
123 	if (optptr != NULL)
124 		*optptr = ' ';
125 	else if (opt != '?') {
126 	warn:
127 		/* option '%c' should be listed in the options string */
128 		warning(339, opt);
129 	}
130 }
131 
132 static void
133 check_unhandled_option(void)
134 {
135 	const char *opt;
136 
137 	lint_assert(ck.options != NULL);
138 
139 	for (opt = ck.options; *opt != '\0'; opt++) {
140 		if (*opt == ' ' || *opt == ':')
141 			continue;
142 
143 		/* option '%c' should be handled in the switch */
144 		warning_at(338, &ck.options_pos, *opt);
145 	}
146 }
147 
148 
149 void
150 check_getopt_begin_while(const tnode_t *tn)
151 {
152 	if (ck.while_level == 0) {
153 		if (!is_getopt_condition(tn, &ck.options))
154 			return;
155 		ck.options_pos = curr_pos;
156 	}
157 	ck.while_level++;
158 }
159 
160 void
161 check_getopt_begin_switch(void)
162 {
163 	if (ck.while_level > 0)
164 		ck.switch_level++;
165 }
166 
167 void
168 check_getopt_case_label(int64_t value)
169 {
170 	if (ck.switch_level == 1 && value == (char)value)
171 		check_unlisted_option((char)value);
172 }
173 
174 void
175 check_getopt_end_switch(void)
176 {
177 	if (ck.switch_level == 0)
178 		return;
179 
180 	ck.switch_level--;
181 	if (ck.switch_level == 0)
182 		check_unhandled_option();
183 }
184 
185 void
186 check_getopt_end_while(void)
187 {
188 	if (ck.while_level == 0)
189 		return;
190 
191 	ck.while_level--;
192 	if (ck.while_level != 0)
193 		return;
194 
195 	free(ck.options);
196 	ck.options = NULL;
197 }
198