gcc/ada/get_targ.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             G E T _ T A R G                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2018, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 --  This package provides an Import to the C functions which provide
  27 --  values related to types on the target system. It is only needed for
  28 --  exp_dbug and the elaboration of ttypes, via the Set_Targs package.
  29 --  It also contains the routine for registering floating-point types.
  30
  31 --  NOTE: Any changes in this package must be reflected in aa_getta.adb
  32 --  and any other version in the various back ends.
  33
  34 --  Note that all these values return sizes of C types with corresponding
  35 --  names. This allows GNAT to define the corresponding Ada types to have
  36 --  the same representation. There is one exception to this general rule:
  37 --  the Wide_Character_Type uses twice the size of a C char, instead of the
  38 --  size of wchar_t.
  39
  40 with Einfo; use Einfo;
  41 with Types; use Types;
  42
  43 package Get_Targ is
  44
  45    --  Functions returning individual runtime values
  46
  47    function Get_Bits_Per_Unit              return Pos;
  48    --  System.Storage_Unit
  49
  50    function Get_Bits_Per_Word              return Pos;
  51    --  System.Word_Size
  52
  53    function Get_Char_Size                  return Pos;
  54    --  Size of Standard.Character
  55
  56    function Get_Wchar_T_Size               return Pos;
  57    --  Size of Interfaces.C.wchar_t
  58
  59    function Get_Short_Size                 return Pos;
  60    --  Size of Standard.Short_Integer
  61
  62    function Get_Int_Size                   return Pos;
  63    --  Size of Standard.Integer
  64
  65    function Get_Long_Size                  return Pos;
  66    --  Size of Standard.Long_Integer
  67
  68    function Get_Long_Long_Size             return Pos;
  69    --  Size of Standard.Long_Long_Integer
  70
  71    function Get_Pointer_Size               return Pos;
  72    --  Size of System.Address
  73
  74    function Get_Maximum_Alignment          return Pos;
  75    --  Maximum supported alignment
  76
  77    function Get_Float_Words_BE             return Nat;
  78    --  Non-zero iff float words big endian
  79
  80    function Get_Words_BE                   return Nat;
  81    --  Non-zero iff integer words big endian
  82
  83    function Get_Bytes_BE                   return Nat;
  84    --  Non-zero iff bytes big-endian
  85
  86    function Get_Bits_BE                    return Nat;
  87    --  Non-zero iff bit order big endian
  88
  89    function Get_Strict_Alignment           return Nat;
  90    --  Non-zero if target requires strict alignent
  91
  92    function Get_System_Allocator_Alignment return Nat;
  93    --  Alignment guaranteed by malloc falls
  94
  95    function Get_Double_Float_Alignment     return Nat;
  96    --  Alignment required for Long_Float or 0 if no special requirement
  97
  98    function Get_Double_Scalar_Alignment    return Nat;
  99    --  Alignment required for Long_Long_Integer or larger integer types
 100    --  or 0 if no special requirement.
 101
 102    function Get_Short_Enums                return Int;
 103    --  Returns non-zero if we are in short enums mode, where foreign convention
 104    --  (in particular C and C++) enumeration types will be sized as in Ada,
 105    --  using the shortest possibility from 8,16,32 bits, signed or unsigned.
 106    --  A zero value means Short_Enums are not in use, and in this case all
 107    --  foreign convention enumeration types are given the same size as c int.
 108
 109    --  Other subprograms
 110
 111    function Get_Max_Unaligned_Field return Pos;
 112    --  Returns the maximum supported size in bits for a field that is
 113    --  not aligned on a storage unit boundary.
 114
 115    function Width_From_Size  (Size : Pos) return Pos;
 116    function Digits_From_Size (Size : Pos) return Pos;
 117    --  Calculate values for 'Width or 'Digits from 'Size
 118
 119    type C_String is array (0 .. 255) of aliased Character;
 120    pragma Convention (C, C_String);
 121
 122    type Register_Type_Proc is access procedure
 123      (C_Name    : C_String;       -- Nul-terminated string with name of type
 124       Digs      : Natural;        -- Digits for floating point, 0 otherwise
 125       Complex   : Boolean;        -- True iff type has real and imaginary parts
 126       Count     : Natural;        -- Number of elements in vector, 0 otherwise
 127       Float_Rep : Float_Rep_Kind; -- Representation used for fpt type
 128       Precision : Positive;       -- Precision of representation in bits
 129       Size      : Positive;       -- Size of representation in bits
 130       Alignment : Natural);       -- Required alignment in bits
 131    pragma Convention (C, Register_Type_Proc);
 132    --  Call back procedure for Register_Back_End_Types. This is to be used by
 133    --  Create_Standard to create predefined types for all types supported by
 134    --  the back end.
 135
 136    procedure Register_Back_End_Types (Call_Back : Register_Type_Proc);
 137    --  Calls the Call_Back function with information for each supported type
 138
 139    function Get_Back_End_Config_File return String_Ptr;
 140    --  Return the back end configuration file, or null if none. If non-null,
 141    --  this file should be used instead of calling the various Get_xxx
 142    --  functions in this package.
 143
 144 end Get_Targ;