text: #ifndef UTIL_H
  #define UTIL_H
  
  #include <stdarg.h>
  #include <stdbool.h>
  #include <getopt.h>
  
  /*
   * Copyright 2011 The Chromium Authors, All Rights Reserved.
   * Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation; either version 2 of the
   * License, or (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   *  General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
   *                                                                   USA
   */
  
  #ifdef __GNUC__
  #define PRINTF(i, j)	__attribute__((format (printf, i, j)))
  #define NORETURN	__attribute__((noreturn))
  #else
  #define PRINTF(i, j)
  #define NORETURN
  #endif
  
  #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  
  #define stringify(s)	stringify_(s)
  #define stringify_(s)	#s
  
  static inline void NORETURN PRINTF(1, 2) die(const char *str, ...)
  {
  	va_list ap;
  
  	va_start(ap, str);
  	fprintf(stderr, "FATAL ERROR: ");
  	vfprintf(stderr, str, ap);
  	va_end(ap);
  	exit(1);
  }
  
  static inline void *xmalloc(size_t len)
  {
  	void *new = malloc(len);
  
  	if (!new)
  		die("malloc() failed\n");
  
  	return new;
  }
  
  static inline void *xrealloc(void *p, size_t len)
  {
  	void *new = realloc(p, len);
  
  	if (!new)
  		die("realloc() failed (len=%zd)\n", len);
  
  	return new;
  }
  
  extern char *xstrdup(const char *s);
  
  extern int PRINTF(2, 3) xasprintf(char **strp, const char *fmt, ...);
  extern char *join_path(const char *path, const char *name);
  
  /**
   * Check a property of a given length to see if it is all printable and
   * has a valid terminator. The property can contain either a single string,
   * or multiple strings each of non-zero length.
   *
   * @param data	The string to check
   * @param len	The string length including terminator
   * @return 1 if a valid printable string, 0 if not
   */
  bool util_is_printable_string(const void *data, int len);
  
  /*
   * Parse an escaped character starting at index i in string s.  The resulting
   * character will be returned and the index i will be updated to point at the
   * character directly after the end of the encoding, this may be the '\0'
   * terminator of the string.
   */
  char get_escape_char(const char *s, int *i);
  
  /**
   * Read a device tree file into a buffer. This will report any errors on
   * stderr.
   *
   * @param filename	The filename to read, or - for stdin
   * @return Pointer to allocated buffer containing fdt, or NULL on error
   */
  char *utilfdt_read(const char *filename);
  
  /**
   * Like utilfdt_read(), but also passes back the size of the file read.
   *
   * @param len		If non-NULL, the amount of data we managed to read
   */
  char *utilfdt_read_len(const char *filename, off_t *len);
  
  /**
   * Read a device tree file into a buffer. Does not report errors, but only
   * returns them. The value returned can be passed to strerror() to obtain
   * an error message for the user.
   *
   * @param filename	The filename to read, or - for stdin
   * @param buffp		Returns pointer to buffer containing fdt
   * @return 0 if ok, else an errno value representing the error
   */
  int utilfdt_read_err(const char *filename, char **buffp);
  
  /**
   * Like utilfdt_read_err(), but also passes back the size of the file read.
   *
   * @param len		If non-NULL, the amount of data we managed to read
   */
  int utilfdt_read_err_len(const char *filename, char **buffp, off_t *len);
  
  /**
   * Write a device tree buffer to a file. This will report any errors on
   * stderr.
   *
   * @param filename	The filename to write, or - for stdout
   * @param blob		Poiner to buffer containing fdt
   * @return 0 if ok, -1 on error
   */
  int utilfdt_write(const char *filename, const void *blob);
  
  /**
   * Write a device tree buffer to a file. Does not report errors, but only
   * returns them. The value returned can be passed to strerror() to obtain
   * an error message for the user.
   *
   * @param filename	The filename to write, or - for stdout
   * @param blob		Poiner to buffer containing fdt
   * @return 0 if ok, else an errno value representing the error
   */
  int utilfdt_write_err(const char *filename, const void *blob);
  
  /**
   * Decode a data type string. The purpose of this string
   *
   * The string consists of an optional character followed by the type:
   *	Modifier characters:
   *		hh or b	1 byte
   *		h	2 byte
   *		l	4 byte, default
   *
   *	Type character:
   *		s	string
   *		i	signed integer
   *		u	unsigned integer
   *		x	hex
   *
   * TODO: Implement ll modifier (8 bytes)
   * TODO: Implement o type (octal)
   *
   * @param fmt		Format string to process
   * @param type		Returns type found(s/d/u/x), or 0 if none
   * @param size		Returns size found(1,2,4,8) or 4 if none
   * @return 0 if ok, -1 on error (no type given, or other invalid format)
   */
  int utilfdt_decode_type(const char *fmt, int *type, int *size);
  
  /*
   * This is a usage message fragment for the -t option. It is the format
   * supported by utilfdt_decode_type.
   */
  
  #define USAGE_TYPE_MSG \
  	"<type>\ts=string, i=int, u=unsigned, x=hex\n" \
  	"\tOptional modifier prefix:\n" \
  	"\t\thh or b=byte, h=2 byte, l=4 byte (default)";
  
  /**
   * Print property data in a readable format to stdout
   *
   * Properties that look like strings will be printed as strings. Otherwise
   * the data will be displayed either as cells (if len is a multiple of 4
   * bytes) or bytes.
   *
   * If len is 0 then this function does nothing.
   *
   * @param data	Pointers to property data
   * @param len	Length of property data
   */
  void utilfdt_print_data(const char *data, int len);
  
  /**
   * Show source version and exit
   */
  void NORETURN util_version(void);
  
  /**
   * Show usage and exit
   *
   * This helps standardize the output of various utils.  You most likely want
   * to use the usage() helper below rather than call this.
   *
   * @param errmsg	If non-NULL, an error message to display
   * @param synopsis	The initial example usage text (and possible examples)
   * @param short_opts	The string of short options
   * @param long_opts	The structure of long options
   * @param opts_help	An array of help strings (should align with long_opts)
   */
  void NORETURN util_usage(const char *errmsg, const char *synopsis,
  			 const char *short_opts,
  			 struct option const long_opts[],
  			 const char * const opts_help[]);
  
  /**
   * Show usage and exit
   *
   * If you name all your usage variables with usage_xxx, then you can call this
   * help macro rather than expanding all arguments yourself.
   *
   * @param errmsg	If non-NULL, an error message to display
   */
  #define usage(errmsg) \
  	util_usage(errmsg, usage_synopsis, usage_short_opts, \
  		   usage_long_opts, usage_opts_help)
  
  /**
   * Call getopt_long() with standard options
   *
   * Since all util code runs getopt in the same way, provide a helper.
   */
  #define util_getopt_long() getopt_long(argc, argv, usage_short_opts, \
  				       usage_long_opts, NULL)
  
  /* Helper for aligning long_opts array */
  #define a_argument required_argument
  
  /* Helper for usage_short_opts string constant */
  #define USAGE_COMMON_SHORT_OPTS "hV"
  
  /* Helper for usage_long_opts option array */
  #define USAGE_COMMON_LONG_OPTS \
  	{"help",      no_argument, NULL, 'h'}, \
  	{"version",   no_argument, NULL, 'V'}, \
  	{NULL,        no_argument, NULL, 0x0}
  
  /* Helper for usage_opts_help array */
  #define USAGE_COMMON_OPTS_HELP \
  	"Print this help and exit", \
  	"Print version and exit", \
  	NULL
  
  /* Helper for getopt case statements */
  #define case_USAGE_COMMON_FLAGS \
  	case 'h': usage(NULL); \
  	case 'V': util_version(); \
  	case '?': usage("unknown option");
  
  #endif /* UTIL_H */
  