PR rtl-optimization/79386
[official-gcc.git] / gcc / ada / system-rtems.ads
blobce1ce2bda3a4acc52493c7fa7b9fcd83d2ef16c6
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- S Y S T E M --
6 -- --
7 -- S p e c --
8 -- (Compiler Version) --
9 -- --
10 -- Copyright (C) 1992-2016 Free Software Foundation, Inc. --
11 -- --
12 -- This specification is derived from the Ada Reference Manual for use with --
13 -- GNAT. The copyright notice above, and the license provisions that follow --
14 -- apply solely to the contents of the part following the private keyword. --
15 -- --
16 -- GNAT is free software; you can redistribute it and/or modify it under --
17 -- terms of the GNU General Public License as published by the Free Soft- --
18 -- ware Foundation; either version 3, or (at your option) any later ver- --
19 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
20 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
21 -- or FITNESS FOR A PARTICULAR PURPOSE. --
22 -- --
23 -- As a special exception under Section 7 of GPL version 3, you are granted --
24 -- additional permissions described in the GCC Runtime Library Exception, --
25 -- version 3.1, as published by the Free Software Foundation. --
26 -- --
27 -- You should have received a copy of the GNU General Public License and --
28 -- a copy of the GCC Runtime Library Exception along with this program; --
29 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
30 -- <http://www.gnu.org/licenses/>. --
31 -- --
32 -- GNAT was originally developed by the GNAT team at New York University. --
33 -- Extensive contributions were provided by Ada Core Technologies Inc. --
34 -- --
35 ------------------------------------------------------------------------------
37 -- This version is for RTEMS. It is based as closely as possible on the
38 -- generic version with the following exceptions:
39 -- + priority definitions
41 package System is
42 pragma Pure;
43 -- Note that we take advantage of the implementation permission to make
44 -- this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
45 -- 2005, this is Pure in any case (AI-362).
47 pragma No_Elaboration_Code_All;
48 -- Allow the use of that restriction in units that WITH this unit
50 type Name is (SYSTEM_NAME_GNAT);
51 System_Name : constant Name := SYSTEM_NAME_GNAT;
53 -- System-Dependent Named Numbers
55 Min_Int : constant := Long_Long_Integer'First;
56 Max_Int : constant := Long_Long_Integer'Last;
58 Max_Binary_Modulus : constant := 2 ** Long_Long_Integer'Size;
59 Max_Nonbinary_Modulus : constant := Integer'Last;
61 Max_Base_Digits : constant := Long_Long_Float'Digits;
62 Max_Digits : constant := Long_Long_Float'Digits;
64 Max_Mantissa : constant := 63;
65 Fine_Delta : constant := 2.0 ** (-Max_Mantissa);
67 Tick : constant := 0.01;
69 -- Storage-related Declarations
71 type Address is private;
72 pragma Preelaborable_Initialization (Address);
73 Null_Address : constant Address;
75 Storage_Unit : constant := Standard'Storage_Unit;
76 Word_Size : constant := Standard'Word_Size;
77 Memory_Size : constant := 2 ** Standard'Address_Size;
79 -- Address comparison
81 function "<" (Left, Right : Address) return Boolean;
82 function "<=" (Left, Right : Address) return Boolean;
83 function ">" (Left, Right : Address) return Boolean;
84 function ">=" (Left, Right : Address) return Boolean;
85 function "=" (Left, Right : Address) return Boolean;
87 pragma Import (Intrinsic, "<");
88 pragma Import (Intrinsic, "<=");
89 pragma Import (Intrinsic, ">");
90 pragma Import (Intrinsic, ">=");
91 pragma Import (Intrinsic, "=");
93 -- Other System-Dependent Declarations
95 type Bit_Order is (High_Order_First, Low_Order_First);
96 Default_Bit_Order : constant Bit_Order :=
97 Bit_Order'Val (Standard'Default_Bit_Order);
98 pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
100 -- Priority-related Declarations (RM D.1)
102 -- RTEMS POSIX threads support 256 priority levels with 255 being
103 -- logically the most important. Levels 0 and 255 are reserved.
105 -- 255 is reserved for RTEMS system tasks
106 -- 247 - 254 correspond to hardware interrupt levels 0 .. 7
107 -- 246 is a catchall default "interrupt" priority for signals,
108 -- allowing higher priority than normal tasks, but lower than
109 -- hardware priority levels. Protected Object ceilings can
110 -- override these values.
111 -- 245 is used by the Interrupt_Manager task
112 -- 0 is reserved for the RTEMS IDLE task and really should not
113 -- be accessible from Ada but GNAT initializes
114 -- Current_Priority to 0 so it must be valid
116 Max_Priority : constant Positive := 244;
117 Max_Interrupt_Priority : constant Positive := 254;
119 subtype Any_Priority is Integer range 0 .. 254;
120 subtype Priority is Any_Priority range 0 .. 244;
121 subtype Interrupt_Priority is Any_Priority range 245 .. 254;
123 Default_Priority : constant Priority := 122;
125 private
127 type Address is mod Memory_Size;
128 Null_Address : constant Address := 0;
130 --------------------------------------
131 -- System Implementation Parameters --
132 --------------------------------------
134 -- These parameters provide information about the target that is used
135 -- by the compiler. They are in the private part of System, where they
136 -- can be accessed using the special circuitry in the Targparm unit
137 -- whose source should be consulted for more detailed descriptions
138 -- of the individual switch values.
140 Backend_Divide_Checks : constant Boolean := False;
141 Backend_Overflow_Checks : constant Boolean := True;
142 Command_Line_Args : constant Boolean := True;
143 Configurable_Run_Time : constant Boolean := False;
144 Denorm : constant Boolean := True;
145 Duration_32_Bits : constant Boolean := False;
146 Exit_Status_Supported : constant Boolean := True;
147 Fractional_Fixed_Ops : constant Boolean := False;
148 Frontend_Layout : constant Boolean := False;
149 Machine_Overflows : constant Boolean := False;
150 Machine_Rounds : constant Boolean := True;
151 Preallocated_Stacks : constant Boolean := False;
152 Signed_Zeros : constant Boolean := True;
153 Stack_Check_Default : constant Boolean := False;
154 Stack_Check_Probes : constant Boolean := False;
155 Stack_Check_Limits : constant Boolean := False;
156 Support_Aggregates : constant Boolean := True;
157 Support_Composite_Assign : constant Boolean := True;
158 Support_Composite_Compare : constant Boolean := True;
159 Support_Long_Shifts : constant Boolean := True;
160 Always_Compatible_Rep : constant Boolean := False;
161 Suppress_Standard_Library : constant Boolean := False;
162 Use_Ada_Main_Program_Name : constant Boolean := False;
163 Frontend_Exceptions : constant Boolean := True;
164 ZCX_By_Default : constant Boolean := False;
166 end System;