1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E T _ T A R G -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2013-2014, 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 handles setting target dependent parameters. If the -gnatet 27-- switch is not set, then these values are taken from the back end (via the 28-- routines in Get_Targ, and the enumerate_modes routine in misc.c). If the 29-- switch is set, then the values are read from the target.atp file in the 30-- current directory (usually written with the Write_Target_Dependent_Values 31-- procedure defined in this package). 32 33-- Note that all these values return sizes of C types with corresponding 34-- names. This allows GNAT to define the corresponding Ada types to have 35-- the same representation. There is one exception: the representation 36-- of Wide_Character_Type uses twice the size of a C char, instead of the 37-- size of wchar_t, since this corresponds to expected Ada usage. 38 39with Einfo; use Einfo; 40with Types; use Types; 41 42package Set_Targ is 43 44 ----------------------------- 45 -- Target-Dependent Values -- 46 ----------------------------- 47 48 -- The following is a table of target dependent values. In normal operation 49 -- these values are set by calling the appropriate C backend routines that 50 -- interface to back end routines that determine target characteristics. 51 52 -- If the -gnateT switch is used, then any values that are read from the 53 -- file target.atp in the current directory overwrite values set from the 54 -- back end. This is used by tools other than the compiler, e.g. to do 55 -- semantic analysis of programs that will run on some other target than 56 -- the machine on which the tool is run. 57 58 -- Note: fields marked with a question mark are boolean fields, where a 59 -- value of 0 is False, and a value of 1 is True. 60 61 Bits_BE : Nat; -- Bits stored big-endian? 62 Bits_Per_Unit : Pos; -- Bits in a storage unit 63 Bits_Per_Word : Pos; -- Bits in a word 64 Bytes_BE : Nat; -- Bytes stored big-endian? 65 Char_Size : Pos; -- Standard.Character'Size 66 Double_Float_Alignment : Nat; -- Alignment of double float 67 Double_Scalar_Alignment : Nat; -- Alignment of double length scalar 68 Double_Size : Pos; -- Standard.Long_Float'Size 69 Float_Size : Pos; -- Standard.Float'Size 70 Float_Words_BE : Nat; -- Float words stored big-endian? 71 Int_Size : Pos; -- Standard.Integer'Size 72 Long_Double_Size : Pos; -- Standard.Long_Long_Float'Size 73 Long_Long_Size : Pos; -- Standard.Long_Long_Integer'Size 74 Long_Size : Pos; -- Standard.Long_Integer'Size 75 Maximum_Alignment : Pos; -- Maximum permitted alignment 76 Max_Unaligned_Field : Pos; -- Maximum size for unaligned bit field 77 Pointer_Size : Pos; -- System.Address'Size 78 Short_Enums : Nat; -- Foreign enums use short size? 79 Short_Size : Pos; -- Standard.Short_Integer'Size 80 Strict_Alignment : Nat; -- Strict alignment? 81 System_Allocator_Alignment : Nat; -- Alignment for malloc calls 82 Wchar_T_Size : Pos; -- Interfaces.C.wchar_t'Size 83 Words_BE : Nat; -- Words stored big-endian? 84 85 ------------------------------------- 86 -- Registered Floating-Point Types -- 87 ------------------------------------- 88 89 -- This table contains the list of modes supported by the back-end as 90 -- provided by the back end routine enumerate_modes in misc.c. Note that 91 -- we only store floating-point modes (see Register_Float_Type). 92 93 type FPT_Mode_Entry is record 94 NAME : String_Ptr; -- Name of mode (no null character at end) 95 DIGS : Natural; -- Digits for floating-point type 96 FLOAT_REP : Float_Rep_Kind; -- Float representation 97 PRECISION : Natural; -- Precision in bits 98 SIZE : Natural; -- Size in bits 99 ALIGNMENT : Natural; -- Alignment in bits 100 end record; 101 102 FPT_Mode_Table : array (1 .. 1000) of FPT_Mode_Entry; 103 Num_FPT_Modes : Natural := 0; 104 -- Table containing the supported modes and number of entries 105 106 ----------------- 107 -- Subprograms -- 108 ----------------- 109 110 procedure Write_Target_Dependent_Values; 111 -- This routine writes the file target.atp in the current directory with 112 -- the values of the global target parameters as listed above, and as set 113 -- by prior calls to Initialize/Read_Target_Dependent_Values. The format 114 -- of the target.atp file is as follows 115 -- 116 -- First come the values of the variables defined in this spec: 117 -- 118 -- One line per value 119 -- 120 -- name value 121 -- 122 -- where name is the name of the parameter, spelled out in full, 123 -- and cased as in the above list, and value is an unsigned decimal 124 -- integer. Two or more blanks separates the name from the value. 125 -- 126 -- All the variables must be present, in alphabetical order (i.e. the 127 -- same order as the declarations in this spec). 128 -- 129 -- Then there is a blank line to separate the two parts of the file. Then 130 -- come the lines showing the floating-point types to be registered. 131 -- 132 -- One line per registered mode 133 -- 134 -- name digs float_rep precision alignment 135 -- 136 -- where name is the string name of the type (which can have single 137 -- spaces embedded in the name (e.g. long double). The name is followed 138 -- by at least two blanks. The following fields are as described above 139 -- for a Mode_Entry (where float_rep is I/V/A for IEEE-754-Binary, 140 -- Vax_Native, AAMP), fields are separated by at least one blank, and 141 -- a LF character immediately follows the alignment field. 142 -- 143 -- ??? We do not write the size for backward compatibility reasons, 144 -- which means that target.atp will not be a complete description for 145 -- the very peculiar cases where the size cannot be computed from the 146 -- precision and the alignment by the formula: 147 -- 148 -- size := (precision + alignment - 1) / alignment * alignment 149 150end Set_Targ; 151