text: /* util.h
   * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   *
   * Logging and other utility functions.
   */
  
  #ifndef _UTIL_H_
  #define _UTIL_H_
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/types.h>
  #include <syslog.h>
  #include <unistd.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /*
   * Silence compiler warnings for unused variables/functions.
   *
   * If the definition is actually used, the attribute should be removed, but if
   * it's forgotten or left in place, it doesn't cause a problem.
   *
   * If the definition is actually unused, the compiler is free to remove it from
   * the output so as to save size.  If you want to make sure the definition is
   * kept (e.g. for ABI compatibility), look at the "used" attribute instead.
   */
  #define attribute_unused __attribute__((__unused__))
  
  /*
   * Mark the symbol as "weak" in the ELF output.  This provides a fallback symbol
   * that may be overriden at link time.  See this page for more details:
   * https://en.wikipedia.org/wiki/Weak_symbol
   */
  #define attribute_weak __attribute__((__weak__))
  
  /*
   * Mark the function as a printf-style function.
   * @format_idx The index in the function argument list where the format string
   *             is passed (where the first argument is "1").
   * @check_idx The index in the function argument list where the first argument
   *            used in the format string is passed.
   * Some examples:
   *   foo([1] const char *format, [2] ...): format=1 check=2
   *   foo([1] int, [2] const char *format, [3] ...): format=2 check=3
   *   foo([1] const char *format, [2] const char *, [3] ...): format=1 check=3
   */
  #define attribute_printf(format_idx, check_idx) \
  	__attribute__((__format__(__printf__, format_idx, check_idx)))
  
  /* clang-format off */
  #define die(_msg, ...) \
  	do_fatal_log(LOG_ERR, "libminijail[%d]: " _msg, getpid(), ## __VA_ARGS__)
  
  #define pdie(_msg, ...) \
  	die(_msg ": %m", ## __VA_ARGS__)
  
  #define warn(_msg, ...) \
  	do_log(LOG_WARNING, "libminijail[%d]: " _msg, getpid(), ## __VA_ARGS__)
  
  #define pwarn(_msg, ...) \
  	warn(_msg ": %m", ## __VA_ARGS__)
  
  #define info(_msg, ...) \
  	do_log(LOG_INFO, "libminijail[%d]: " _msg, getpid(), ## __VA_ARGS__)
  
  #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  /* clang-format on */
  
  extern const char *log_syscalls[];
  extern const size_t log_syscalls_len;
  
  enum logging_system_t {
  	/* Log to syslog. This is the default. */
  	LOG_TO_SYSLOG = 0,
  
  	/* Log to a file descriptor. */
  	LOG_TO_FD,
  };
  
  /*
   * Even though this function internally calls abort(2)/exit(2), it is
   * intentionally not marked with the noreturn attribute. When marked as
   * noreturn, clang coalesces several of the do_fatal_log() calls in methods that
   * have a large number of such calls (like minijail_enter()), making it
   * impossible for breakpad to correctly identify the line where it was called,
   * making the backtrace somewhat useless.
   */
  extern void do_fatal_log(int priority, const char *format, ...)
      attribute_printf(2, 3);
  
  extern void do_log(int priority, const char *format, ...)
      attribute_printf(2, 3);
  
  static inline int is_android(void)
  {
  #if defined(__ANDROID__)
  	return 1;
  #else
  	return 0;
  #endif
  }
  
  void __asan_init(void) attribute_weak;
  void __hwasan_init(void) attribute_weak;
  
  static inline int running_with_asan(void)
  {
  	return &__asan_init != 0 || &__hwasan_init != 0;
  }
  
  int lookup_syscall(const char *name);
  const char *lookup_syscall_name(int nr);
  
  long int parse_single_constant(char *constant_str, char **endptr);
  long int parse_constant(char *constant_str, char **endptr);
  int parse_size(size_t *size, const char *sizespec);
  
  char *strip(char *s);
  
  /*
   * tokenize: locate the next token in @stringp using the @delim
   * @stringp A pointer to the string to scan for tokens
   * @delim   The delimiter to split by
   *
   * Note that, unlike strtok, @delim is not a set of characters, but the full
   * delimiter.  e.g. "a,;b,;c" with a delim of ",;" will yield ["a","b","c"].
   *
   * Note that, unlike strtok, this may return an empty token.  e.g. "a,,b" with
   * strtok will yield ["a","b"], but this will yield ["a","","b"].
   */
  char *tokenize(char **stringp, const char *delim);
  
  char *path_join(const char *external_path, const char *internal_path);
  
  /*
   * consumebytes: consumes @length bytes from a buffer @buf of length @buflength
   * @length    Number of bytes to consume
   * @buf       Buffer to consume from
   * @buflength Size of @buf
   *
   * Returns a pointer to the base of the bytes, or NULL for errors.
   */
  void *consumebytes(size_t length, char **buf, size_t *buflength);
  
  /*
   * consumestr: consumes a C string from a buffer @buf of length @length
   * @buf    Buffer to consume
   * @length Length of buffer
   *
   * Returns a pointer to the base of the string, or NULL for errors.
   */
  char *consumestr(char **buf, size_t *buflength);
  
  /*
   * init_logging: initializes the module-wide logging.
   * @logger       The logging system to use.
   * @fd           The file descriptor to log into. Ignored unless
   *               @logger = LOG_TO_FD.
   * @min_priority The minimum priority to display. Corresponds to syslog's
                   priority parameter. Ignored unless @logger = LOG_TO_FD.
   */
  void init_logging(enum logging_system_t logger, int fd, int min_priority);
  
  #ifdef __cplusplus
  }; /* extern "C" */
  #endif
  
  #endif /* _UTIL_H_ */
  