util.h revision 318102
1#ifndef _UTIL_H
2#define _UTIL_H
3
4#include <stdarg.h>
5#include <stdbool.h>
6#include <getopt.h>
7
8/*
9 * Copyright 2011 The Chromium Authors, All Rights Reserved.
10 * Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
16 *
17 *  This program is distributed in the hope that it will be useful,
18 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20 *  General Public License for more details.
21 *
22 *  You should have received a copy of the GNU General Public License
23 *  along with this program; if not, write to the Free Software
24 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
25 *                                                                   USA
26 */
27
28#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
29
30#ifdef __GNUC__
31static inline void
32__attribute__((noreturn)) __attribute__((format (printf, 1, 2)))
33die(const char *str, ...)
34#else
35static inline void die(const char *str, ...)
36#endif
37{
38	va_list ap;
39
40	va_start(ap, str);
41	fprintf(stderr, "FATAL ERROR: ");
42	vfprintf(stderr, str, ap);
43	va_end(ap);
44	exit(1);
45}
46
47static inline void *xmalloc(size_t len)
48{
49	void *new = malloc(len);
50
51	if (!new)
52		die("malloc() failed\n");
53
54	return new;
55}
56
57static inline void *xrealloc(void *p, size_t len)
58{
59	void *new = realloc(p, len);
60
61	if (!new)
62		die("realloc() failed (len=%zd)\n", len);
63
64	return new;
65}
66
67extern char *xstrdup(const char *s);
68
69#ifdef __GNUC__
70extern int __attribute__((format (printf, 2, 3)))
71xasprintf(char **strp, const char *fmt, ...);
72#else
73extern int xasprintf(char **strp, const char *fmt, ...);
74#endif
75extern char *join_path(const char *path, const char *name);
76
77/**
78 * Check a property of a given length to see if it is all printable and
79 * has a valid terminator. The property can contain either a single string,
80 * or multiple strings each of non-zero length.
81 *
82 * @param data	The string to check
83 * @param len	The string length including terminator
84 * @return 1 if a valid printable string, 0 if not
85 */
86bool util_is_printable_string(const void *data, int len);
87
88/*
89 * Parse an escaped character starting at index i in string s.  The resulting
90 * character will be returned and the index i will be updated to point at the
91 * character directly after the end of the encoding, this may be the '\0'
92 * terminator of the string.
93 */
94char get_escape_char(const char *s, int *i);
95
96/**
97 * Read a device tree file into a buffer. This will report any errors on
98 * stderr.
99 *
100 * @param filename	The filename to read, or - for stdin
101 * @return Pointer to allocated buffer containing fdt, or NULL on error
102 */
103char *utilfdt_read(const char *filename);
104
105/**
106 * Like utilfdt_read(), but also passes back the size of the file read.
107 *
108 * @param len		If non-NULL, the amount of data we managed to read
109 */
110char *utilfdt_read_len(const char *filename, off_t *len);
111
112/**
113 * Read a device tree file into a buffer. Does not report errors, but only
114 * returns them. The value returned can be passed to strerror() to obtain
115 * an error message for the user.
116 *
117 * @param filename	The filename to read, or - for stdin
118 * @param buffp		Returns pointer to buffer containing fdt
119 * @return 0 if ok, else an errno value representing the error
120 */
121int utilfdt_read_err(const char *filename, char **buffp);
122
123/**
124 * Like utilfdt_read_err(), but also passes back the size of the file read.
125 *
126 * @param len		If non-NULL, the amount of data we managed to read
127 */
128int utilfdt_read_err_len(const char *filename, char **buffp, off_t *len);
129
130/**
131 * Write a device tree buffer to a file. This will report any errors on
132 * stderr.
133 *
134 * @param filename	The filename to write, or - for stdout
135 * @param blob		Poiner to buffer containing fdt
136 * @return 0 if ok, -1 on error
137 */
138int utilfdt_write(const char *filename, const void *blob);
139
140/**
141 * Write a device tree buffer to a file. Does not report errors, but only
142 * returns them. The value returned can be passed to strerror() to obtain
143 * an error message for the user.
144 *
145 * @param filename	The filename to write, or - for stdout
146 * @param blob		Poiner to buffer containing fdt
147 * @return 0 if ok, else an errno value representing the error
148 */
149int utilfdt_write_err(const char *filename, const void *blob);
150
151/**
152 * Decode a data type string. The purpose of this string
153 *
154 * The string consists of an optional character followed by the type:
155 *	Modifier characters:
156 *		hh or b	1 byte
157 *		h	2 byte
158 *		l	4 byte, default
159 *
160 *	Type character:
161 *		s	string
162 *		i	signed integer
163 *		u	unsigned integer
164 *		x	hex
165 *
166 * TODO: Implement ll modifier (8 bytes)
167 * TODO: Implement o type (octal)
168 *
169 * @param fmt		Format string to process
170 * @param type		Returns type found(s/d/u/x), or 0 if none
171 * @param size		Returns size found(1,2,4,8) or 4 if none
172 * @return 0 if ok, -1 on error (no type given, or other invalid format)
173 */
174int utilfdt_decode_type(const char *fmt, int *type, int *size);
175
176/*
177 * This is a usage message fragment for the -t option. It is the format
178 * supported by utilfdt_decode_type.
179 */
180
181#define USAGE_TYPE_MSG \
182	"<type>\ts=string, i=int, u=unsigned, x=hex\n" \
183	"\tOptional modifier prefix:\n" \
184	"\t\thh or b=byte, h=2 byte, l=4 byte (default)";
185
186/**
187 * Print property data in a readable format to stdout
188 *
189 * Properties that look like strings will be printed as strings. Otherwise
190 * the data will be displayed either as cells (if len is a multiple of 4
191 * bytes) or bytes.
192 *
193 * If len is 0 then this function does nothing.
194 *
195 * @param data	Pointers to property data
196 * @param len	Length of property data
197 */
198void utilfdt_print_data(const char *data, int len);
199
200/**
201 * Show source version and exit
202 */
203void util_version(void) __attribute__((noreturn));
204
205/**
206 * Show usage and exit
207 *
208 * This helps standardize the output of various utils.  You most likely want
209 * to use the usage() helper below rather than call this.
210 *
211 * @param errmsg	If non-NULL, an error message to display
212 * @param synopsis	The initial example usage text (and possible examples)
213 * @param short_opts	The string of short options
214 * @param long_opts	The structure of long options
215 * @param opts_help	An array of help strings (should align with long_opts)
216 */
217void util_usage(const char *errmsg, const char *synopsis,
218		const char *short_opts, struct option const long_opts[],
219		const char * const opts_help[]) __attribute__((noreturn));
220
221/**
222 * Show usage and exit
223 *
224 * If you name all your usage variables with usage_xxx, then you can call this
225 * help macro rather than expanding all arguments yourself.
226 *
227 * @param errmsg	If non-NULL, an error message to display
228 */
229#define usage(errmsg) \
230	util_usage(errmsg, usage_synopsis, usage_short_opts, \
231		   usage_long_opts, usage_opts_help)
232
233/**
234 * Call getopt_long() with standard options
235 *
236 * Since all util code runs getopt in the same way, provide a helper.
237 */
238#define util_getopt_long() getopt_long(argc, argv, usage_short_opts, \
239				       usage_long_opts, NULL)
240
241/* Helper for aligning long_opts array */
242#define a_argument required_argument
243
244/* Helper for usage_short_opts string constant */
245#define USAGE_COMMON_SHORT_OPTS "hV"
246
247/* Helper for usage_long_opts option array */
248#define USAGE_COMMON_LONG_OPTS \
249	{"help",      no_argument, NULL, 'h'}, \
250	{"version",   no_argument, NULL, 'V'}, \
251	{NULL,        no_argument, NULL, 0x0}
252
253/* Helper for usage_opts_help array */
254#define USAGE_COMMON_OPTS_HELP \
255	"Print this help and exit", \
256	"Print version and exit", \
257	NULL
258
259/* Helper for getopt case statements */
260#define case_USAGE_COMMON_FLAGS \
261	case 'h': usage(NULL); \
262	case 'V': util_version(); \
263	case '?': usage("unknown option");
264
265#endif /* _UTIL_H */
266