1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . S T A N D A R D _ L I B R A R Y -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2011, 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 package is included in all programs. It contains declarations that 33-- are required to be part of every Ada program. A special mechanism is 34-- required to ensure that these are loaded, since it may be the case in 35-- some programs that the only references to these required packages are 36-- from C code or from code generated directly by Gigi, and in both cases 37-- the binder is not aware of such references. 38 39-- System.Standard_Library also includes data that must be present in every 40-- program, in particular data for all the standard exceptions, and also some 41-- subprograms that must be present in every program. 42 43-- The binder unconditionally includes s-stalib.ali, which ensures that this 44-- package and the packages it references are included in all Ada programs, 45-- together with the included data. 46 47pragma Compiler_Unit; 48 49pragma Polling (Off); 50-- We must turn polling off for this unit, because otherwise we get 51-- elaboration circularities with Ada.Exceptions if polling is on. 52 53with Ada.Unchecked_Conversion; 54 55package System.Standard_Library is 56 pragma Warnings (Off); 57 pragma Preelaborate_05; 58 pragma Warnings (On); 59 60 subtype Big_String is String (1 .. Positive'Last); 61 pragma Suppress_Initialization (Big_String); 62 -- Type used to obtain string access to given address. Initialization is 63 -- suppressed, since we never want to have variables of this type, and 64 -- we never want to attempt initialiazation of virtual variables of this 65 -- type (e.g. when pragma Normalize_Scalars is used). 66 67 type Big_String_Ptr is access all Big_String; 68 for Big_String_Ptr'Storage_Size use 0; 69 -- We use this access type to pass a pointer to an area of storage to be 70 -- accessed as a string. Of course when this pointer is used, it is the 71 -- responsibility of the accessor to ensure proper bounds. The storage 72 -- size clause ensures we do not allocate variables of this type. 73 74 function To_Ptr is 75 new Ada.Unchecked_Conversion (System.Address, Big_String_Ptr); 76 77 --------------------------------------------- 78 -- Type For Enumeration Image Index Tables -- 79 --------------------------------------------- 80 81 -- Note: these types are declared at the start of this unit, since 82 -- they must appear before any enumeration types declared in this 83 -- unit. Note that the spec of system is already elaborated at 84 -- this point (since we are a child of system), which means that 85 -- enumeration types in package System cannot use these types. 86 87 type Image_Index_Table_8 is 88 array (Integer range <>) of Short_Short_Integer; 89 type Image_Index_Table_16 is 90 array (Integer range <>) of Short_Integer; 91 type Image_Index_Table_32 is 92 array (Integer range <>) of Integer; 93 -- These types are used to generate the index vector used for enumeration 94 -- type image tables. See spec of Exp_Imgv in the main GNAT sources for a 95 -- full description of the data structures that are used here. 96 97 ------------------------------------- 98 -- Exception Declarations and Data -- 99 ------------------------------------- 100 101 type Raise_Action is access procedure; 102 -- A pointer to a procedure used in the Raise_Hook field 103 104 type Exception_Data; 105 type Exception_Data_Ptr is access all Exception_Data; 106 -- An equivalent of Exception_Id that is public 107 108 type Exception_Code is mod 2 ** Integer'Size; 109 -- A scalar value bound to some exception data. Typically used for 110 -- imported or exported exceptions on VMS. Having a separate type for this 111 -- is useful to enforce consistency throughout the various run-time units 112 -- handling such codes, and having it unsigned is the most appropriate 113 -- choice for it's currently single use on VMS. 114 115 -- ??? The construction in Cstand has no way to access the proper type 116 -- node for Exception_Code, and currently uses Standard_Unsigned as a 117 -- fallback. The representations shall match, and the size clause below 118 -- is aimed at ensuring that. 119 120 for Exception_Code'Size use Integer'Size; 121 122 -- The following record defines the underlying representation of exceptions 123 124 -- WARNING! Any changes to this may need to be reflected in the following 125 -- locations in the compiler and runtime code: 126 127 -- 1. The Internal_Exception routine in s-exctab.adb 128 -- 2. The processing in gigi that tests Not_Handled_By_Others 129 -- 3. Expand_N_Exception_Declaration in Exp_Ch11 130 -- 4. The construction of the exception type in Cstand 131 132 type Exception_Data is record 133 Not_Handled_By_Others : Boolean; 134 -- Normally set False, indicating that the exception is handled in the 135 -- usual way by others (i.e. an others handler handles the exception). 136 -- Set True to indicate that this exception is not caught by others 137 -- handlers, but must be explicitly named in a handler. This latter 138 -- setting is currently used by the Abort_Signal. 139 140 Lang : Character; 141 -- A character indicating the language raising the exception. 142 -- Set to "A" for exceptions defined by an Ada program. 143 -- Set to "V" for imported VMS exceptions. 144 145 Name_Length : Natural; 146 -- Length of fully expanded name of exception 147 148 Full_Name : System.Address; 149 -- Fully expanded name of exception, null terminated 150 -- You can use To_Ptr to convert this to a string. 151 152 HTable_Ptr : Exception_Data_Ptr; 153 -- Hash table pointer used to link entries together in the hash table 154 -- built (by Register_Exception in s-exctab.adb) for converting between 155 -- identities and names. 156 157 Import_Code : Exception_Code; 158 -- Value for imported exceptions. Needed only for the handling of 159 -- Import/Export_Exception for the VMS case, but present in all 160 -- implementations (we might well extend this mechanism for other 161 -- systems in the future). 162 163 Raise_Hook : Raise_Action; 164 -- This field can be used to place a "hook" on an exception. If the 165 -- value is non-null, then it points to a procedure which is called 166 -- whenever the exception is raised. This call occurs immediately, 167 -- before any other actions taken by the raise (and in particular 168 -- before any unwinding of the stack occurs). 169 end record; 170 171 -- Definitions for standard predefined exceptions defined in Standard, 172 173 -- Why are the NULs necessary here, seems like they should not be 174 -- required, since Gigi is supposed to add a Nul to each name ??? 175 176 Constraint_Error_Name : constant String := "CONSTRAINT_ERROR" & ASCII.NUL; 177 Program_Error_Name : constant String := "PROGRAM_ERROR" & ASCII.NUL; 178 Storage_Error_Name : constant String := "STORAGE_ERROR" & ASCII.NUL; 179 Tasking_Error_Name : constant String := "TASKING_ERROR" & ASCII.NUL; 180 Abort_Signal_Name : constant String := "_ABORT_SIGNAL" & ASCII.NUL; 181 182 Numeric_Error_Name : constant String := "NUMERIC_ERROR" & ASCII.NUL; 183 -- This is used only in the Ada 83 case, but it is not worth having a 184 -- separate version of s-stalib.ads for use in Ada 83 mode. 185 186 Constraint_Error_Def : aliased Exception_Data := 187 (Not_Handled_By_Others => False, 188 Lang => 'A', 189 Name_Length => Constraint_Error_Name'Length, 190 Full_Name => Constraint_Error_Name'Address, 191 HTable_Ptr => null, 192 Import_Code => 0, 193 Raise_Hook => null); 194 195 Numeric_Error_Def : aliased Exception_Data := 196 (Not_Handled_By_Others => False, 197 Lang => 'A', 198 Name_Length => Numeric_Error_Name'Length, 199 Full_Name => Numeric_Error_Name'Address, 200 HTable_Ptr => null, 201 Import_Code => 0, 202 Raise_Hook => null); 203 204 Program_Error_Def : aliased Exception_Data := 205 (Not_Handled_By_Others => False, 206 Lang => 'A', 207 Name_Length => Program_Error_Name'Length, 208 Full_Name => Program_Error_Name'Address, 209 HTable_Ptr => null, 210 Import_Code => 0, 211 Raise_Hook => null); 212 213 Storage_Error_Def : aliased Exception_Data := 214 (Not_Handled_By_Others => False, 215 Lang => 'A', 216 Name_Length => Storage_Error_Name'Length, 217 Full_Name => Storage_Error_Name'Address, 218 HTable_Ptr => null, 219 Import_Code => 0, 220 Raise_Hook => null); 221 222 Tasking_Error_Def : aliased Exception_Data := 223 (Not_Handled_By_Others => False, 224 Lang => 'A', 225 Name_Length => Tasking_Error_Name'Length, 226 Full_Name => Tasking_Error_Name'Address, 227 HTable_Ptr => null, 228 Import_Code => 0, 229 Raise_Hook => null); 230 231 Abort_Signal_Def : aliased Exception_Data := 232 (Not_Handled_By_Others => True, 233 Lang => 'A', 234 Name_Length => Abort_Signal_Name'Length, 235 Full_Name => Abort_Signal_Name'Address, 236 HTable_Ptr => null, 237 Import_Code => 0, 238 Raise_Hook => null); 239 240 pragma Export (C, Constraint_Error_Def, "constraint_error"); 241 pragma Export (C, Numeric_Error_Def, "numeric_error"); 242 pragma Export (C, Program_Error_Def, "program_error"); 243 pragma Export (C, Storage_Error_Def, "storage_error"); 244 pragma Export (C, Tasking_Error_Def, "tasking_error"); 245 pragma Export (C, Abort_Signal_Def, "_abort_signal"); 246 247 Local_Partition_ID : Natural := 0; 248 -- This variable contains the local Partition_ID that will be used when 249 -- building exception occurrences. In distributed mode, it will be 250 -- set by each partition to the correct value during the elaboration. 251 252 type Exception_Trace_Kind is 253 (RM_Convention, 254 -- No particular trace is requested, only unhandled exceptions 255 -- in the environment task (following the RM) will be printed. 256 -- This is the default behavior. 257 258 Every_Raise, 259 -- Denotes every possible raise event, either explicit or due to 260 -- a specific language rule, within the context of a task or not. 261 262 Unhandled_Raise 263 -- Denotes the raise events corresponding to exceptions for which 264 -- there is no user defined handler. 265 ); 266 -- Provide a way to denote different kinds of automatic traces related 267 -- to exceptions that can be requested. 268 269 Exception_Trace : Exception_Trace_Kind := RM_Convention; 270 pragma Atomic (Exception_Trace); 271 -- By default, follow the RM convention 272 273 ----------------- 274 -- Subprograms -- 275 ----------------- 276 277 procedure Abort_Undefer_Direct; 278 pragma Inline (Abort_Undefer_Direct); 279 -- A little procedure that just calls Abort_Undefer.all, for use in 280 -- clean up procedures, which only permit a simple subprogram name. 281 282 procedure Adafinal; 283 -- Performs the Ada Runtime finalization the first time it is invoked. 284 -- All subsequent calls are ignored. 285 286end System.Standard_Library; 287