xref: /linux/scripts/dtc/util.h (revision 9792d660a4e91d31a6b1af105ae3f1c29107e94b)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef UTIL_H
3 #define UTIL_H
4 
5 #include <stdlib.h>
6 #include <stdarg.h>
7 #include <stdbool.h>
8 #include <getopt.h>
9 
10 /*
11  * Copyright 2011 The Chromium Authors, All Rights Reserved.
12  * Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
13  */
14 
15 #ifdef __GNUC__
16 #ifdef __MINGW_PRINTF_FORMAT
17 #define PRINTF(i, j)	__attribute__((format (__MINGW_PRINTF_FORMAT, i, j)))
18 #elif __GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
19 #define PRINTF(i, j)	__attribute__((format (gnu_printf, i, j)))
20 #else
21 #define PRINTF(i, j)	__attribute__((format (printf, i, j)))
22 #endif
23 #define NORETURN	__attribute__((noreturn))
24 #else
25 #define PRINTF(i, j)
26 #define NORETURN
27 #endif
28 
29 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
30 
31 #define stringify(s)	stringify_(s)
32 #define stringify_(s)	#s
33 
34 static inline void NORETURN PRINTF(1, 2) die(const char *str, ...)
35 {
36 	va_list ap;
37 
38 	va_start(ap, str);
39 	fprintf(stderr, "FATAL ERROR: ");
40 	vfprintf(stderr, str, ap);
41 	va_end(ap);
42 	exit(1);
43 }
44 
45 /**
46  * Writes path to fp, escaping spaces with a backslash.
47  */
48 void fprint_path_escaped(FILE *fp, const char *path);
49 
50 static inline void *xmalloc(size_t len)
51 {
52 	void *new = malloc(len);
53 
54 	if (!new)
55 		die("malloc() failed\n");
56 
57 	return new;
58 }
59 
60 static inline void *xrealloc(void *p, size_t len)
61 {
62 	void *new = realloc(p, len);
63 
64 	if (!new)
65 		die("realloc() failed (len=%zd)\n", len);
66 
67 	return new;
68 }
69 
70 extern char *xstrdup(const char *s);
71 extern char *xstrndup(const char *s, size_t len);
72 
73 extern int PRINTF(2, 3) xasprintf(char **strp, const char *fmt, ...);
74 extern int PRINTF(2, 3) xasprintf_append(char **strp, const char *fmt, ...);
75 extern int PRINTF(2, 0) xavsprintf_append(char **strp, const char *fmt, va_list ap);
76 extern char *join_path(const char *path, const char *name);
77 
78 /**
79  * Check a property of a given length to see if it is all printable and
80  * has a valid terminator. The property can contain either a single string,
81  * or multiple strings each of non-zero length.
82  *
83  * @param data	The string to check
84  * @param len	The string length including terminator
85  * @return 1 if a valid printable string, 0 if not
86  */
87 bool util_is_printable_string(const void *data, int len);
88 
89 /*
90  * Parse an escaped character starting at index i in string s.  The resulting
91  * character will be returned and the index i will be updated to point at the
92  * character directly after the end of the encoding, this may be the '\0'
93  * terminator of the string.
94  */
95 char get_escape_char(const char *s, int *i);
96 
97 /**
98  * Read a device tree file into a buffer. This will report any errors on
99  * stderr.
100  *
101  * @param filename	The filename to read, or - for stdin
102  * @param len		If non-NULL, the amount of data we managed to read
103  * @return Pointer to allocated buffer containing fdt, or NULL on error
104  */
105 char *utilfdt_read(const char *filename, size_t *len);
106 
107 /**
108  * Read a device tree file into a buffer. Does not report errors, but only
109  * returns them. The value returned can be passed to strerror() to obtain
110  * an error message for the user.
111  *
112  * @param filename	The filename to read, or - for stdin
113  * @param buffp		Returns pointer to buffer containing fdt
114  * @param len		If non-NULL, the amount of data we managed to read
115  * @return 0 if ok, else an errno value representing the error
116  */
117 int utilfdt_read_err(const char *filename, char **buffp, size_t *len);
118 
119 /**
120  * Write a device tree buffer to a file. This will report any errors on
121  * stderr.
122  *
123  * @param filename	The filename to write, or - for stdout
124  * @param blob		Pointer to buffer containing fdt
125  * @return 0 if ok, -1 on error
126  */
127 int utilfdt_write(const char *filename, const void *blob);
128 
129 /**
130  * Write a device tree buffer to a file. Does not report errors, but only
131  * returns them. The value returned can be passed to strerror() to obtain
132  * an error message for the user.
133  *
134  * @param filename	The filename to write, or - for stdout
135  * @param blob		Pointer to buffer containing fdt
136  * @return 0 if ok, else an errno value representing the error
137  */
138 int utilfdt_write_err(const char *filename, const void *blob);
139 
140 /**
141  * Decode a data type string. The purpose of this string
142  *
143  * The string consists of an optional character followed by the type:
144  *	Modifier characters:
145  *		hh or b	1 byte
146  *		h	2 byte
147  *		l	4 byte, default
148  *
149  *	Type character:
150  *		s	string
151  *		i	signed integer
152  *		u	unsigned integer
153  *		x	hex
154  *		r	raw
155  *
156  * TODO: Implement ll modifier (8 bytes)
157  * TODO: Implement o type (octal)
158  *
159  * @param fmt		Format string to process
160  * @param type		Returns type found(s/d/u/x), or 0 if none
161  * @param size		Returns size found(1,2,4,8) or 4 if none
162  * @return 0 if ok, -1 on error (no type given, or other invalid format)
163  */
164 int utilfdt_decode_type(const char *fmt, int *type, int *size);
165 
166 /*
167  * This is a usage message fragment for the -t option. It is the format
168  * supported by utilfdt_decode_type.
169  */
170 
171 #define USAGE_TYPE_MSG \
172 	"<type>\ts=string, i=int, u=unsigned, x=hex, r=raw\n" \
173 	"\tOptional modifier prefix:\n" \
174 	"\t\thh or b=byte, h=2 byte, l=4 byte (default)";
175 
176 /**
177  * Print property data in a readable format to stdout
178  *
179  * Properties that look like strings will be printed as strings. Otherwise
180  * the data will be displayed either as cells (if len is a multiple of 4
181  * bytes) or bytes.
182  *
183  * If len is 0 then this function does nothing.
184  *
185  * @param data	Pointers to property data
186  * @param len	Length of property data
187  */
188 void utilfdt_print_data(const char *data, int len);
189 
190 /**
191  * Show source version and exit
192  */
193 void NORETURN util_version(void);
194 
195 /**
196  * Show usage and exit
197  *
198  * This helps standardize the output of various utils.  You most likely want
199  * to use the usage() helper below rather than call this.
200  *
201  * @param errmsg	If non-NULL, an error message to display
202  * @param synopsis	The initial example usage text (and possible examples)
203  * @param short_opts	The string of short options
204  * @param long_opts	The structure of long options
205  * @param opts_help	An array of help strings (should align with long_opts)
206  */
207 void NORETURN util_usage(const char *errmsg, const char *synopsis,
208 			 const char *short_opts,
209 			 struct option const long_opts[],
210 			 const char * const opts_help[]);
211 
212 /**
213  * Show usage and exit
214  *
215  * If you name all your usage variables with usage_xxx, then you can call this
216  * help macro rather than expanding all arguments yourself.
217  *
218  * @param errmsg	If non-NULL, an error message to display
219  */
220 #define usage(errmsg) \
221 	util_usage(errmsg, usage_synopsis, usage_short_opts, \
222 		   usage_long_opts, usage_opts_help)
223 
224 /**
225  * Call getopt_long() with standard options
226  *
227  * Since all util code runs getopt in the same way, provide a helper.
228  */
229 #define util_getopt_long() getopt_long(argc, argv, usage_short_opts, \
230 				       usage_long_opts, NULL)
231 
232 /* Helper for aligning long_opts array */
233 #define a_argument required_argument
234 
235 /* Helper for usage_short_opts string constant */
236 #define USAGE_COMMON_SHORT_OPTS "hV"
237 
238 /* Helper for usage_long_opts option array */
239 #define USAGE_COMMON_LONG_OPTS \
240 	{"help",      no_argument, NULL, 'h'}, \
241 	{"version",   no_argument, NULL, 'V'}, \
242 	{NULL,        no_argument, NULL, 0x0}
243 
244 /* Helper for usage_opts_help array */
245 #define USAGE_COMMON_OPTS_HELP \
246 	"Print this help and exit", \
247 	"Print version and exit", \
248 	NULL
249 
250 /* Helper for getopt case statements */
251 #define case_USAGE_COMMON_FLAGS \
252 	case 'h': usage(NULL); \
253 	case 'V': util_version(); \
254 	case '?': usage("unknown option");
255 
256 #endif /* UTIL_H */
257