src/lib/gnat/i-c.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                         I N T E R F A C E S . C                          --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 -- This specification is derived from the Ada Reference Manual for use with --
  10 -- GNAT.  In accordance with the copyright of that document, you can freely --
  11 -- copy and modify this specification,  provided that if you redistribute a --
  12 -- modified version,  any changes that you have made are clearly indicated. --
  13 --                                                                          --
  14 ------------------------------------------------------------------------------
  15
  16 with System.Parameters;
  17
  18 package Interfaces.C is
  19    pragma Pure;
  20
  21    --  Declaration's based on C's <limits.h>
  22
  23    CHAR_BIT  : constant := 8;
  24    SCHAR_MIN : constant := -128;
  25    SCHAR_MAX : constant := 127;
  26    UCHAR_MAX : constant := 255;
  27
  28    --  Signed and Unsigned Integers. Note that in GNAT, we have ensured that
  29    --  the standard predefined Ada types correspond to the standard C types
  30
  31    --  Note: the Integer qualifications used in the declaration of type long
  32    --  avoid ambiguities when compiling in the presence of s-auxdec.ads and
  33    --  a non-private system.address type.
  34
  35    type int   is new Integer;
  36    type short is new Short_Integer;
  37    type long  is range -(2 ** (System.Parameters.long_bits - Integer'(1)))
  38      .. +(2 ** (System.Parameters.long_bits - Integer'(1))) - 1;
  39
  40    type signed_char is range SCHAR_MIN .. SCHAR_MAX;
  41    for signed_char'Size use CHAR_BIT;
  42
  43    type unsigned       is mod 2 ** int'Size;
  44    type unsigned_short is mod 2 ** short'Size;
  45    type unsigned_long  is mod 2 ** long'Size;
  46
  47    type unsigned_char is mod (UCHAR_MAX + 1);
  48    for unsigned_char'Size use CHAR_BIT;
  49
  50    subtype plain_char is unsigned_char; -- ??? should be parameterized
  51
  52    --  Note: the Integer qualifications used in the declaration of ptrdiff_t
  53    --  avoid ambiguities when compiling in the presence of s-auxdec.ads and
  54    --  a non-private system.address type.
  55
  56    type ptrdiff_t is
  57      range -(2 ** (System.Parameters.ptr_bits - Integer'(1))) ..
  58            +(2 ** (System.Parameters.ptr_bits - Integer'(1)) - 1);
  59
  60    type size_t is mod 2 ** System.Parameters.ptr_bits;
  61
  62    --  For convenience, also provide an uintptr_t type
  63    type uintptr_t is mod 2 ** System.Parameters.ptr_bits;
  64
  65    ----------------------------
  66    -- Characters and Strings --
  67    ----------------------------
  68
  69    type char is new Character;
  70
  71    nul : constant char := char'First;
  72
  73    function To_C   (Item : Character) return char;
  74    function To_Ada (Item : char)      return Character;
  75
  76    type char_array is array (size_t range <>) of aliased char;
  77    for char_array'Component_Size use CHAR_BIT;
  78
  79    function Is_Nul_Terminated (Item : char_array) return Boolean;
  80
  81 end Interfaces.C;