xref: /linux/scripts/dtc/util.h (revision 088e88be5a380cc4e81963a9a02815da465d144f)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef UTIL_H
3 #define UTIL_H
4 
5 #include <stdarg.h>
6 #include <stdbool.h>
7 #include <getopt.h>
8 
9 /*
10  * Copyright 2011 The Chromium Authors, All Rights Reserved.
11  * Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
12  */
13 
14 #ifdef __GNUC__
15 #define PRINTF(i, j)	__attribute__((format (printf, i, j)))
16 #define NORETURN	__attribute__((noreturn))
17 #else
18 #define PRINTF(i, j)
19 #define NORETURN
20 #endif
21 
22 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
23 
24 #define stringify(s)	stringify_(s)
25 #define stringify_(s)	#s
26 
27 static inline void NORETURN PRINTF(1, 2) die(const char *str, ...)
28 {
29 	va_list ap;
30 
31 	va_start(ap, str);
32 	fprintf(stderr, "FATAL ERROR: ");
33 	vfprintf(stderr, str, ap);
34 	va_end(ap);
35 	exit(1);
36 }
37 
38 static inline void *xmalloc(size_t len)
39 {
40 	void *new = malloc(len);
41 
42 	if (!new)
43 		die("malloc() failed\n");
44 
45 	return new;
46 }
47 
48 static inline void *xrealloc(void *p, size_t len)
49 {
50 	void *new = realloc(p, len);
51 
52 	if (!new)
53 		die("realloc() failed (len=%zd)\n", len);
54 
55 	return new;
56 }
57 
58 extern char *xstrdup(const char *s);
59 
60 extern int PRINTF(2, 3) xasprintf(char **strp, const char *fmt, ...);
61 extern int PRINTF(2, 3) xasprintf_append(char **strp, const char *fmt, ...);
62 extern int xavsprintf_append(char **strp, const char *fmt, va_list ap);
63 extern char *join_path(const char *path, const char *name);
64 
65 /**
66  * Check a property of a given length to see if it is all printable and
67  * has a valid terminator. The property can contain either a single string,
68  * or multiple strings each of non-zero length.
69  *
70  * @param data	The string to check
71  * @param len	The string length including terminator
72  * @return 1 if a valid printable string, 0 if not
73  */
74 bool util_is_printable_string(const void *data, int len);
75 
76 /*
77  * Parse an escaped character starting at index i in string s.  The resulting
78  * character will be returned and the index i will be updated to point at the
79  * character directly after the end of the encoding, this may be the '\0'
80  * terminator of the string.
81  */
82 char get_escape_char(const char *s, int *i);
83 
84 /**
85  * Read a device tree file into a buffer. This will report any errors on
86  * stderr.
87  *
88  * @param filename	The filename to read, or - for stdin
89  * @param len		If non-NULL, the amount of data we managed to read
90  * @return Pointer to allocated buffer containing fdt, or NULL on error
91  */
92 char *utilfdt_read(const char *filename, size_t *len);
93 
94 /**
95  * Read a device tree file into a buffer. Does not report errors, but only
96  * returns them. The value returned can be passed to strerror() to obtain
97  * an error message for the user.
98  *
99  * @param filename	The filename to read, or - for stdin
100  * @param buffp		Returns pointer to buffer containing fdt
101  * @param len		If non-NULL, the amount of data we managed to read
102  * @return 0 if ok, else an errno value representing the error
103  */
104 int utilfdt_read_err(const char *filename, char **buffp, size_t *len);
105 
106 /**
107  * Write a device tree buffer to a file. This will report any errors on
108  * stderr.
109  *
110  * @param filename	The filename to write, or - for stdout
111  * @param blob		Pointer to buffer containing fdt
112  * @return 0 if ok, -1 on error
113  */
114 int utilfdt_write(const char *filename, const void *blob);
115 
116 /**
117  * Write a device tree buffer to a file. Does not report errors, but only
118  * returns them. The value returned can be passed to strerror() to obtain
119  * an error message for the user.
120  *
121  * @param filename	The filename to write, or - for stdout
122  * @param blob		Pointer to buffer containing fdt
123  * @return 0 if ok, else an errno value representing the error
124  */
125 int utilfdt_write_err(const char *filename, const void *blob);
126 
127 /**
128  * Decode a data type string. The purpose of this string
129  *
130  * The string consists of an optional character followed by the type:
131  *	Modifier characters:
132  *		hh or b	1 byte
133  *		h	2 byte
134  *		l	4 byte, default
135  *
136  *	Type character:
137  *		s	string
138  *		i	signed integer
139  *		u	unsigned integer
140  *		x	hex
141  *
142  * TODO: Implement ll modifier (8 bytes)
143  * TODO: Implement o type (octal)
144  *
145  * @param fmt		Format string to process
146  * @param type		Returns type found(s/d/u/x), or 0 if none
147  * @param size		Returns size found(1,2,4,8) or 4 if none
148  * @return 0 if ok, -1 on error (no type given, or other invalid format)
149  */
150 int utilfdt_decode_type(const char *fmt, int *type, int *size);
151 
152 /*
153  * This is a usage message fragment for the -t option. It is the format
154  * supported by utilfdt_decode_type.
155  */
156 
157 #define USAGE_TYPE_MSG \
158 	"<type>\ts=string, i=int, u=unsigned, x=hex\n" \
159 	"\tOptional modifier prefix:\n" \
160 	"\t\thh or b=byte, h=2 byte, l=4 byte (default)";
161 
162 /**
163  * Print property data in a readable format to stdout
164  *
165  * Properties that look like strings will be printed as strings. Otherwise
166  * the data will be displayed either as cells (if len is a multiple of 4
167  * bytes) or bytes.
168  *
169  * If len is 0 then this function does nothing.
170  *
171  * @param data	Pointers to property data
172  * @param len	Length of property data
173  */
174 void utilfdt_print_data(const char *data, int len);
175 
176 /**
177  * Show source version and exit
178  */
179 void NORETURN util_version(void);
180 
181 /**
182  * Show usage and exit
183  *
184  * This helps standardize the output of various utils.  You most likely want
185  * to use the usage() helper below rather than call this.
186  *
187  * @param errmsg	If non-NULL, an error message to display
188  * @param synopsis	The initial example usage text (and possible examples)
189  * @param short_opts	The string of short options
190  * @param long_opts	The structure of long options
191  * @param opts_help	An array of help strings (should align with long_opts)
192  */
193 void NORETURN util_usage(const char *errmsg, const char *synopsis,
194 			 const char *short_opts,
195 			 struct option const long_opts[],
196 			 const char * const opts_help[]);
197 
198 /**
199  * Show usage and exit
200  *
201  * If you name all your usage variables with usage_xxx, then you can call this
202  * help macro rather than expanding all arguments yourself.
203  *
204  * @param errmsg	If non-NULL, an error message to display
205  */
206 #define usage(errmsg) \
207 	util_usage(errmsg, usage_synopsis, usage_short_opts, \
208 		   usage_long_opts, usage_opts_help)
209 
210 /**
211  * Call getopt_long() with standard options
212  *
213  * Since all util code runs getopt in the same way, provide a helper.
214  */
215 #define util_getopt_long() getopt_long(argc, argv, usage_short_opts, \
216 				       usage_long_opts, NULL)
217 
218 /* Helper for aligning long_opts array */
219 #define a_argument required_argument
220 
221 /* Helper for usage_short_opts string constant */
222 #define USAGE_COMMON_SHORT_OPTS "hV"
223 
224 /* Helper for usage_long_opts option array */
225 #define USAGE_COMMON_LONG_OPTS \
226 	{"help",      no_argument, NULL, 'h'}, \
227 	{"version",   no_argument, NULL, 'V'}, \
228 	{NULL,        no_argument, NULL, 0x0}
229 
230 /* Helper for usage_opts_help array */
231 #define USAGE_COMMON_OPTS_HELP \
232 	"Print this help and exit", \
233 	"Print version and exit", \
234 	NULL
235 
236 /* Helper for getopt case statements */
237 #define case_USAGE_COMMON_FLAGS \
238 	case 'h': usage(NULL); \
239 	case 'V': util_version(); \
240 	case '?': usage("unknown option");
241 
242 #endif /* UTIL_H */
243