1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . P A R A M E T E R S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2021, 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. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This is the HP version of this package 33 34-- This package defines some system dependent parameters for GNAT. These 35-- are values that are referenced by the runtime library and are therefore 36-- relevant to the target machine. 37 38-- The parameters whose value is defined in the spec are not generally 39-- expected to be changed. If they are changed, it will be necessary to 40-- recompile the run-time library. 41 42-- The parameters which are defined by functions can be changed by modifying 43-- the body of System.Parameters in file s-parame.adb. A change to this body 44-- requires only rebinding and relinking of the application. 45 46-- Note: do not introduce any pragma Inline statements into this unit, since 47-- otherwise the relinking and rebinding capability would be deactivated. 48 49package System.Parameters is 50 pragma Pure; 51 52 --------------------------------------- 53 -- Task And Stack Allocation Control -- 54 --------------------------------------- 55 56 type Size_Type is range 57 -(2 ** (Integer'(Standard'Address_Size) - 1)) .. 58 +(2 ** (Integer'(Standard'Address_Size) - 1)) - 1; 59 -- Type used to provide task stack sizes to the runtime. Sized to permit 60 -- stack sizes of up to half the total addressable memory space. This may 61 -- seem excessively large (even for 32-bit systems), however there are many 62 -- instances of users requiring large stack sizes (for example string 63 -- processing). 64 65 Unspecified_Size : constant Size_Type := Size_Type'First; 66 -- Value used to indicate that no size type is set 67 68 function Default_Stack_Size return Size_Type; 69 -- Default task stack size used if none is specified 70 71 function Minimum_Stack_Size return Size_Type; 72 -- Minimum task stack size permitted 73 74 function Adjust_Storage_Size (Size : Size_Type) return Size_Type; 75 -- Given the storage size stored in the TCB, return the Storage_Size 76 -- value required by the RM for the Storage_Size attribute. The 77 -- required adjustment is as follows: 78 -- 79 -- when Size = Unspecified_Size, return Default_Stack_Size 80 -- when Size < Minimum_Stack_Size, return Minimum_Stack_Size 81 -- otherwise return given Size 82 83 Default_Env_Stack_Size : constant Size_Type := 8_192_000; 84 -- Assumed size of the environment task, if no other information 85 -- is available. This value is used when stack checking is 86 -- enabled and no GNAT_STACK_LIMIT environment variable is set. 87 88 Stack_Grows_Down : constant Boolean := False; 89 -- This constant indicates whether the stack grows up (False) or 90 -- down (True) in memory as functions are called. It is used for 91 -- proper implementation of the stack overflow check. 92 93 Runtime_Default_Sec_Stack_Size : constant Size_Type := 10 * 1024; 94 -- The run-time chosen default size for secondary stacks that may be 95 -- overridden by the user with the use of binder -D switch. 96 97 Sec_Stack_Dynamic : constant Boolean := True; 98 -- Indicates if secondary stacks can grow and shrink at run-time. If False, 99 -- the size of a secondary stack is fixed at the point of its creation. 100 101 ------------------------------------ 102 -- Characteristics of time_t type -- 103 ------------------------------------ 104 105 time_t_bits : constant := Long_Integer'Size; 106 -- Number of bits in type time_t 107 108 ---------------------------------------------- 109 -- Characteristics of Types in Interfaces.C -- 110 ---------------------------------------------- 111 112 long_bits : constant := Long_Integer'Size; 113 -- Number of bits in type long and unsigned_long. The normal convention 114 -- is that this is the same as type Long_Integer, but this may not be true 115 -- of all targets. 116 117 ptr_bits : constant := Standard'Address_Size; 118 subtype C_Address is System.Address; 119 -- Number of bits in Interfaces.C pointers, normally a standard address 120 121 C_Malloc_Linkname : constant String := "__gnat_malloc"; 122 -- Name of runtime function used to allocate such a pointer 123 124 ---------------------------------------------- 125 -- Behavior of Pragma Finalize_Storage_Only -- 126 ---------------------------------------------- 127 128 -- Garbage_Collected is a Boolean constant whose value indicates the 129 -- effect of the pragma Finalize_Storage_Entry on a controlled type. 130 131 -- Garbage_Collected = False 132 133 -- The system releases all storage on program termination only, 134 -- but not other garbage collection occurs, so finalization calls 135 -- are omitted only for outer level objects can be omitted if 136 -- pragma Finalize_Storage_Only is used. 137 138 -- Garbage_Collected = True 139 140 -- The system provides full garbage collection, so it is never 141 -- necessary to release storage for controlled objects for which 142 -- a pragma Finalize_Storage_Only is used. 143 144 Garbage_Collected : constant Boolean := False; 145 -- The storage mode for this system (release on program exit) 146 147 --------------------- 148 -- Tasking Profile -- 149 --------------------- 150 151 -- In the following sections, constant parameters are defined to 152 -- allow some optimizations and fine tuning within the tasking run time 153 -- based on restrictions on the tasking features. 154 155 ------------------- 156 -- Task Abortion -- 157 ------------------- 158 159 No_Abort : constant Boolean := False; 160 -- This constant indicates whether abort statements and asynchronous 161 -- transfer of control (ATC) are disallowed. If set to True, it is 162 -- assumed that neither construct is used, and the run time does not 163 -- need to defer/undefer abort and check for pending actions at 164 -- completion points. A value of True for No_Abort corresponds to: 165 -- pragma Restrictions (No_Abort_Statements); 166 -- pragma Restrictions (Max_Asynchronous_Select_Nesting => 0); 167 168 --------------------- 169 -- Task Attributes -- 170 --------------------- 171 172 Max_Attribute_Count : constant := 32; 173 -- Number of task attributes stored in the task control block 174 175 ----------------------- 176 -- Task Image Length -- 177 ----------------------- 178 179 Max_Task_Image_Length : constant := 256; 180 -- This constant specifies the maximum length of a task's image 181 182 ------------------------------ 183 -- Exception Message Length -- 184 ------------------------------ 185 186 Default_Exception_Msg_Max_Length : constant := 200; 187 -- This constant specifies the default number of characters to allow 188 -- in an exception message (200 is minimum required by RM 11.4.1(18)). 189 190end System.Parameters; 191