support/mph.h

   1 /*
   2  * Common/shared macros and routines.
   3  *
   4  * This file contains macros of the form
   5  *
   6  *   mph_return_if_TYPE_overflow(val);
   7  *
   8  * Which tests `val' for a TYPE underflow/overflow (that is, is `val' within
   9  * the range for TYPE?).  If `val' can't fit in TYPE, errno is set to
  10  * EOVERFLOW, and `return -1' is executed (which is why it's a macro).
  11  *
  12  * Assumptions:
  13  *
  14  * I'm working from GLibc, so that's the basis for my assumptions.  They may
  15  * not be completely portable, in which case I'll need to fix my assumptions.
  16  * :-(
  17  *
  18  * See the typedefs for type size assumptions.  These typedefs *must* be kept
  19  * in sync with the types used in Mono.Posix.dll.
  20  *
  21  * See also:
  22  *   http://developer.apple.com/documentation/Darwin/Reference/ManPages/
  23  */
  24
  25 #ifndef INC_mph_H
  26 #define INC_mph_H
  27
  28 #include <config.h>
  29
  30 #include <limits.h>             /* LONG_MAX, ULONG_MAX */
  31 #include <errno.h>              /* for ERANGE */
  32 #include <glib.h>               /* for g* types, etc. */
  33
  34 #ifdef HAVE_STDINT_H
  35 #include <stdint.h>             /* for SIZE_MAX */
  36 #endif
  37
  38 #if __APPLE__ || __BSD__
  39 #define MPH_ON_BSD
  40 #endif
  41
  42 #ifdef __GNUC__
  43 #define MPH_INTERNAL __attribute__((visibility("hidden")))
  44 #else
  45 #define MPH_INTERNAL
  46 #endif
  47
  48 #if defined (PLATFORM_WIN32) && !defined (EOVERFLOW)
  49 #define EOVERFLOW 75
  50 #endif /* def PLATFORM_WIN32 && ndef EOVERFLOW */
  51
  52 typedef    gint64 mph_blkcnt_t;
  53 typedef    gint64 mph_blksize_t;
  54 typedef   guint64 mph_dev_t;
  55 typedef   guint64 mph_ino_t;
  56 typedef   guint64 mph_nlink_t;
  57 typedef    gint64 mph_off_t;
  58 typedef   guint64 mph_size_t;
  59 typedef    gint64 mph_ssize_t;
  60 typedef    gint32 mph_pid_t;
  61 typedef   guint32 mph_gid_t;
  62 typedef   guint32 mph_uid_t;
  63 typedef    gint64 mph_time_t;
  64 typedef    gint64 mph_clock_t;
  65 typedef   guint64 mph_fsblkcnt_t;
  66 typedef   guint64 mph_fsfilcnt_t;
  67
  68 #ifdef HAVE_LARGE_FILE_SUPPORT
  69 #define MPH_OFF_T_MAX G_MAXINT64
  70 #define MPH_OFF_T_MIN G_MININT64
  71 #else
  72 #define MPH_OFF_T_MAX G_MAXINT32
  73 #define MPH_OFF_T_MIN G_MININT32
  74 #endif
  75
  76 #ifdef SIZE_MAX
  77 #define MPH_SIZE_T_MAX SIZE_MAX
  78 #elif SIZEOF_SIZE_T == 8
  79 #define MPH_SIZE_T_MAX  G_MAXUINT64
  80 #elif SIZEOF_SIZE_T == 4
  81 #define MPH_SIZE_T_MAX  G_MAXUINT32
  82 #else
  83 #error "sizeof(size_t) is unknown!"
  84 #endif
  85
  86 #define _mph_return_val_if_cb_(val, ret, cb) G_STMT_START{ \
  87         if (cb (val)) { \
  88                 errno = EOVERFLOW; \
  89                 return ret; \
  90         }}G_STMT_END
  91
  92 #define mph_have_long_overflow(var) ((var) > LONG_MAX || (var) < LONG_MIN)
  93
  94 #define mph_return_val_if_long_overflow(var, ret) \
  95         _mph_return_val_if_cb_(var, ret, mph_have_long_overflow)
  96
  97 #define mph_return_if_long_overflow(var) mph_return_val_if_long_overflow(var, -1)
  98
  99 #define mph_have_ulong_overflow(var) ((var) > ULONG_MAX)
 100
 101 #define mph_return_val_if_ulong_overflow(var, ret) \
 102         _mph_return_val_if_cb_(var, ret, mph_have_ulong_overflow)
 103
 104 #define mph_return_if_ulong_overflow(var) mph_return_val_if_ulong_overflow(var, -1)
 105
 106 #define mph_have_size_t_overflow(var) ((var) > MPH_SIZE_T_MAX)
 107
 108 #define mph_return_val_if_size_t_overflow(var, ret) \
 109         _mph_return_val_if_cb_(var, ret, mph_have_size_t_overflow)
 110
 111 #define mph_return_if_size_t_overflow(var) mph_return_val_if_size_t_overflow(var, -1)
 112
 113 #define mph_have_off_t_overflow(var) \
 114         (((var) < MPH_OFF_T_MIN) || ((var) > MPH_OFF_T_MAX))
 115
 116 #define mph_return_val_if_off_t_overflow(var, ret) \
 117         _mph_return_val_if_cb_(var, ret, mph_have_off_t_overflow)
 118
 119 #define mph_return_if_off_t_overflow(var) mph_return_val_if_size_t_overflow(var, -1)
 120
 121 #define mph_return_if_time_t_overflow(var) mph_return_if_long_overflow(var)
 122
 123 /*
 124  * Helper function for functions which use ERANGE (such as getpwnam_r and
 125  * getgrnam_r).  These functions accept buffers which are dynamically
 126  * allocated so that they're only as large as necessary.  However, Linux and
 127  * Mac OS X differ on how to signal an error value.
 128  *
 129  * Linux returns the error value directly, while Mac OS X is more traditional,
 130  * returning -1 and setting errno accordingly.
 131  *
 132  * Unify the checking in one place.
 133  */
 134 static inline int
 135 recheck_range (int ret)
 136 {
 137         if (ret == ERANGE)
 138                 return 1;
 139         if (ret == -1)
 140                 return errno == ERANGE;
 141         return 0;
 142 }
 143
 144 MPH_INTERNAL char*
 145 _mph_copy_structure_strings (
 146         void *to,         const size_t *to_offsets,
 147         const void *from, const size_t *from_offsets,
 148         size_t num_strings);
 149
 150 #endif /* ndef INC_mph_H */
 151
 152 /*
 153  * vim: noexpandtab
 154  */