Mercurial > hg > CbC > CbC_gcc
comparison gcc/ada/libgnat/s-parame__ae653.ads @ 111:04ced10e8804
gcc 7
| author | kono |
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| date | Fri, 27 Oct 2017 22:46:09 +0900 |
| parents | |
| children | 84e7813d76e9 |
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| 68:561a7518be6b | 111:04ced10e8804 |
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| 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) 1992-2017, 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 -- Version is used by VxWorks 653, VxWorks MILS, and VxWorks6 cert Ravenscar | |
| 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 | |
| 49 package System.Parameters is | |
| 50 pragma Pure; | |
| 51 | |
| 52 --------------------------------------- | |
| 53 -- Task And Stack Allocation Control -- | |
| 54 --------------------------------------- | |
| 55 | |
| 56 type Task_Storage_Size is new Integer; | |
| 57 -- Type used in tasking units for task storage size | |
| 58 | |
| 59 type Size_Type is new Task_Storage_Size; | |
| 60 -- Type used to provide task storage size to runtime | |
| 61 | |
| 62 Unspecified_Size : constant Size_Type := Size_Type'First; | |
| 63 -- Value used to indicate that no size type is set | |
| 64 | |
| 65 function Default_Stack_Size return Size_Type; | |
| 66 -- Default task stack size used if none is specified | |
| 67 | |
| 68 function Minimum_Stack_Size return Size_Type; | |
| 69 -- Minimum task stack size permitted | |
| 70 | |
| 71 function Adjust_Storage_Size (Size : Size_Type) return Size_Type; | |
| 72 -- Given the storage size stored in the TCB, return the Storage_Size | |
| 73 -- value required by the RM for the Storage_Size attribute. The | |
| 74 -- required adjustment is as follows: | |
| 75 -- | |
| 76 -- when Size = Unspecified_Size, return Default_Stack_Size | |
| 77 -- when Size < Minimum_Stack_Size, return Minimum_Stack_Size | |
| 78 -- otherwise return given Size | |
| 79 | |
| 80 Default_Env_Stack_Size : constant Size_Type := 14_336; | |
| 81 -- Assumed size of the environment task, if no other information | |
| 82 -- is available. This value is used when stack checking is | |
| 83 -- enabled and no GNAT_STACK_LIMIT environment variable is set. | |
| 84 -- This value is chosen as the VxWorks default stack size is 20kB, | |
| 85 -- and a little more than 4kB is necessary for the run time. | |
| 86 | |
| 87 Stack_Grows_Down : constant Boolean := True; | |
| 88 -- This constant indicates whether the stack grows up (False) or | |
| 89 -- down (True) in memory as functions are called. It is used for | |
| 90 -- proper implementation of the stack overflow check. | |
| 91 | |
| 92 Runtime_Default_Sec_Stack_Size : constant Size_Type := 10 * 1024; | |
| 93 -- The run-time chosen default size for secondary stacks that may be | |
| 94 -- overriden by the user with the use of binder -D switch. | |
| 95 | |
| 96 function Default_Sec_Stack_Size return Size_Type; | |
| 97 -- The default size for secondary stacks that reflects any user specified | |
| 98 -- default via the binder -D switch. | |
| 99 | |
| 100 Sec_Stack_Dynamic : constant Boolean := False; | |
| 101 -- Indicates if secondary stacks can grow and shrink at run-time. If False, | |
| 102 -- the size of a secondary stack is fixed at the point of its creation. | |
| 103 | |
| 104 ---------------------------------------------- | |
| 105 -- Characteristics of types in Interfaces.C -- | |
| 106 ---------------------------------------------- | |
| 107 | |
| 108 long_bits : constant := Long_Integer'Size; | |
| 109 -- Number of bits in type long and unsigned_long. The normal convention | |
| 110 -- is that this is the same as type Long_Integer, but this may not be true | |
| 111 -- of all targets. | |
| 112 | |
| 113 ptr_bits : constant := Standard'Address_Size; | |
| 114 subtype C_Address is System.Address; | |
| 115 -- Number of bits in Interfaces.C pointers, normally a standard address | |
| 116 | |
| 117 C_Malloc_Linkname : constant String := "__gnat_malloc"; | |
| 118 -- Name of runtime function used to allocate such a pointer | |
| 119 | |
| 120 ---------------------------------------------- | |
| 121 -- Behavior of Pragma Finalize_Storage_Only -- | |
| 122 ---------------------------------------------- | |
| 123 | |
| 124 -- Garbage_Collected is a Boolean constant whose value indicates the | |
| 125 -- effect of the pragma Finalize_Storage_Entry on a controlled type. | |
| 126 | |
| 127 -- Garbage_Collected = False | |
| 128 | |
| 129 -- The system releases all storage on program termination only, | |
| 130 -- but not other garbage collection occurs, so finalization calls | |
| 131 -- are omitted only for outer level objects can be omitted if | |
| 132 -- pragma Finalize_Storage_Only is used. | |
| 133 | |
| 134 -- Garbage_Collected = True | |
| 135 | |
| 136 -- The system provides full garbage collection, so it is never | |
| 137 -- necessary to release storage for controlled objects for which | |
| 138 -- a pragma Finalize_Storage_Only is used. | |
| 139 | |
| 140 Garbage_Collected : constant Boolean := False; | |
| 141 -- The storage mode for this system (release on program exit) | |
| 142 | |
| 143 --------------------- | |
| 144 -- Tasking Profile -- | |
| 145 --------------------- | |
| 146 | |
| 147 -- In the following sections, constant parameters are defined to | |
| 148 -- allow some optimizations and fine tuning within the tasking run time | |
| 149 -- based on restrictions on the tasking features. | |
| 150 | |
| 151 ---------------------- | |
| 152 -- Locking Strategy -- | |
| 153 ---------------------- | |
| 154 | |
| 155 Single_Lock : constant Boolean := False; | |
| 156 -- Indicates whether a single lock should be used within the tasking | |
| 157 -- run-time to protect internal structures. If True, a single lock | |
| 158 -- will be used, meaning less locking/unlocking operations, but also | |
| 159 -- more global contention. In general, Single_Lock should be set to | |
| 160 -- True on single processor machines, and to False to multi-processor | |
| 161 -- systems, but this can vary from application to application and also | |
| 162 -- depends on the scheduling policy. | |
| 163 | |
| 164 ------------------- | |
| 165 -- Task Abortion -- | |
| 166 ------------------- | |
| 167 | |
| 168 No_Abort : constant Boolean := False; | |
| 169 -- This constant indicates whether abort statements and asynchronous | |
| 170 -- transfer of control (ATC) are disallowed. If set to True, it is | |
| 171 -- assumed that neither construct is used, and the run time does not | |
| 172 -- need to defer/undefer abort and check for pending actions at | |
| 173 -- completion points. A value of True for No_Abort corresponds to: | |
| 174 -- pragma Restrictions (No_Abort_Statements); | |
| 175 -- pragma Restrictions (Max_Asynchronous_Select_Nesting => 0); | |
| 176 | |
| 177 --------------------- | |
| 178 -- Task Attributes -- | |
| 179 --------------------- | |
| 180 | |
| 181 Max_Attribute_Count : constant := 8; | |
| 182 -- Number of task attributes stored in the task control block | |
| 183 | |
| 184 ----------------------- | |
| 185 -- Task Image Length -- | |
| 186 ----------------------- | |
| 187 | |
| 188 Max_Task_Image_Length : constant := 32; | |
| 189 -- This constant specifies the maximum length of a task's image | |
| 190 | |
| 191 ------------------------------ | |
| 192 -- Exception Message Length -- | |
| 193 ------------------------------ | |
| 194 | |
| 195 Default_Exception_Msg_Max_Length : constant := 200; | |
| 196 -- This constant specifies the default number of characters to allow | |
| 197 -- in an exception message (200 is minimum required by RM 11.4.1(18)). | |
| 198 | |
| 199 end System.Parameters; |