1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E T _ T A R G --
-- --
-- S p e c --
-- --
-- Copyright (C) 2013-2014, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package handles setting target dependent parameters. If the -gnatet
-- switch is not set, then these values are taken from the back end (via the
-- routines in Get_Targ, and the enumerate_modes routine in misc.c). If the
-- switch is set, then the values are read from the target.atp file in the
-- current directory (usually written with the Write_Target_Dependent_Values
-- procedure defined in this package).
-- Note that all these values return sizes of C types with corresponding
-- names. This allows GNAT to define the corresponding Ada types to have
-- the same representation. There is one exception: the representation
-- of Wide_Character_Type uses twice the size of a C char, instead of the
-- size of wchar_t, since this corresponds to expected Ada usage.
with Einfo; use Einfo;
with Stand; use Stand;
with Types; use Types;
package Set_Targ is
-----------------------------
-- Target-Dependent Values --
-----------------------------
-- The following is a table of target dependent values. In normal operation
-- these values are set by calling the appropriate C backend routines that
-- interface to back end routines that determine target characteristics.
-- If the -gnateT switch is used, then any values that are read from the
-- file target.atp in the current directory overwrite values set from the
-- back end. This is used by tools other than the compiler, e.g. to do
-- semantic analysis of programs that will run on some other target than
-- the machine on which the tool is run.
-- Note: fields marked with a question mark are boolean fields, where a
-- value of 0 is False, and a value of 1 is True.
Bits_BE : Nat; -- Bits stored big-endian?
Bits_Per_Unit : Pos; -- Bits in a storage unit
Bits_Per_Word : Pos; -- Bits in a word
Bytes_BE : Nat; -- Bytes stored big-endian?
Char_Size : Pos; -- Standard.Character'Size
Double_Float_Alignment : Nat; -- Alignment of double float
Double_Scalar_Alignment : Nat; -- Alignment of double length scalar
Double_Size : Pos; -- Standard.Long_Float'Size
Float_Size : Pos; -- Standard.Float'Size
Float_Words_BE : Nat; -- Float words stored big-endian?
Int_Size : Pos; -- Standard.Integer'Size
Long_Double_Size : Pos; -- Standard.Long_Long_Float'Size
Long_Long_Size : Pos; -- Standard.Long_Long_Integer'Size
Long_Size : Pos; -- Standard.Long_Integer'Size
Maximum_Alignment : Pos; -- Maximum permitted alignment
Max_Unaligned_Field : Pos; -- Maximum size for unaligned bit field
Pointer_Size : Pos; -- System.Address'Size
Short_Enums : Nat; -- Foreign enums use short size?
Short_Size : Pos; -- Standard.Short_Integer'Size
Strict_Alignment : Nat; -- Strict alignment?
System_Allocator_Alignment : Nat; -- Alignment for malloc calls
Wchar_T_Size : Pos; -- Interfaces.C.wchar_t'Size
Words_BE : Nat; -- Words stored big-endian?
-------------------------------------
-- Registered Floating-Point Types --
-------------------------------------
-- This table contains the list of modes supported by the back-end as
-- provided by the back end routine enumerate_modes in misc.c. Note that
-- we only store floating-point modes (see Register_Float_Type).
type FPT_Mode_Entry is record
NAME : String_Ptr; -- Name of mode (no null character at end)
DIGS : Natural; -- Digits for floating-point type
FLOAT_REP : Float_Rep_Kind; -- Float representation
PRECISION : Natural; -- Precision in bits
SIZE : Natural; -- Size in bits
ALIGNMENT : Natural; -- Alignment in bits
end record;
FPT_Mode_Table : array (1 .. 1000) of FPT_Mode_Entry;
Num_FPT_Modes : Natural := 0;
-- Table containing the supported modes and number of entries
-----------------
-- Subprograms --
-----------------
subtype S_Float_Types is
Standard_Entity_Type range S_Short_Float .. S_Long_Long_Float;
function C_Type_For (T : S_Float_Types) return String;
-- Return the name of a C type supported by the back-end and suitable as
-- a basis to construct the standard Ada floating point type identified by
-- T. This is used as a common ground to feed both ttypes values and the
-- GNAT tree nodes for the standard floating point types.
procedure Write_Target_Dependent_Values;
-- This routine writes the file target.atp in the current directory with
-- the values of the global target parameters as listed above, and as set
-- by prior calls to Initialize/Read_Target_Dependent_Values. The format
-- of the target.atp file is as follows
--
-- First come the values of the variables defined in this spec:
--
-- One line per value
--
-- name value
--
-- where name is the name of the parameter, spelled out in full,
-- and cased as in the above list, and value is an unsigned decimal
-- integer. Two or more blanks separates the name from the value.
--
-- All the variables must be present, in alphabetical order (i.e. the
-- same order as the declarations in this spec).
--
-- Then there is a blank line to separate the two parts of the file. Then
-- come the lines showing the floating-point types to be registered.
--
-- One line per registered mode
--
-- name digs float_rep precision alignment
--
-- where name is the string name of the type (which can have single
-- spaces embedded in the name (e.g. long double). The name is followed
-- by at least two blanks. The following fields are as described above
-- for a Mode_Entry (where float_rep is I/V/A for IEEE-754-Binary,
-- Vax_Native, AAMP), fields are separated by at least one blank, and
-- a LF character immediately follows the alignment field.
--
-- ??? We do not write the size for backward compatibility reasons,
-- which means that target.atp will not be a complete description for
-- the very peculiar cases where the size cannot be computed from the
-- precision and the alignment by the formula:
--
-- size := (precision + alignment - 1) / alignment * alignment
end Set_Targ;
|
