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) 1992-2015, 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_Warning; 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 57 -- Historical note: pragma Preelaborate was surrounded by a pair of pragma 58 -- Warnings (Off/On) to circumvent a bootstrap issue. 59 60 pragma Preelaborate; 61 62 subtype Big_String is String (1 .. Positive'Last); 63 pragma Suppress_Initialization (Big_String); 64 -- Type used to obtain string access to given address. Initialization is 65 -- suppressed, since we never want to have variables of this type, and 66 -- we never want to attempt initialiazation of virtual variables of this 67 -- type (e.g. when pragma Normalize_Scalars is used). 68 69 type Big_String_Ptr is access all Big_String; 70 for Big_String_Ptr'Storage_Size use 0; 71 -- We use this access type to pass a pointer to an area of storage to be 72 -- accessed as a string. Of course when this pointer is used, it is the 73 -- responsibility of the accessor to ensure proper bounds. The storage 74 -- size clause ensures we do not allocate variables of this type. 75 76 function To_Ptr is 77 new Ada.Unchecked_Conversion (System.Address, Big_String_Ptr); 78 79 ------------------------------------- 80 -- Exception Declarations and Data -- 81 ------------------------------------- 82 83 type Raise_Action is access procedure; 84 -- A pointer to a procedure used in the Raise_Hook field 85 86 type Exception_Data; 87 type Exception_Data_Ptr is access all Exception_Data; 88 -- An equivalent of Exception_Id that is public 89 90 -- The following record defines the underlying representation of exceptions 91 92 -- WARNING: Any changes to this may need to be reflected in the following 93 -- locations in the compiler and runtime code: 94 95 -- 1. The Internal_Exception routine in s-exctab.adb 96 -- 2. The processing in gigi that tests Not_Handled_By_Others 97 -- 3. Expand_N_Exception_Declaration in Exp_Ch11 98 -- 4. The construction of the exception type in Cstand 99 100 type Exception_Data is record 101 Not_Handled_By_Others : Boolean; 102 -- Normally set False, indicating that the exception is handled in the 103 -- usual way by others (i.e. an others handler handles the exception). 104 -- Set True to indicate that this exception is not caught by others 105 -- handlers, but must be explicitly named in a handler. This latter 106 -- setting is currently used by the Abort_Signal. 107 108 Lang : Character; 109 -- A character indicating the language raising the exception. 110 -- Set to "A" for exceptions defined by an Ada program. 111 -- Set to "C" for imported C++ exceptions. 112 113 Name_Length : Natural; 114 -- Length of fully expanded name of exception 115 116 Full_Name : System.Address; 117 -- Fully expanded name of exception, null terminated 118 -- You can use To_Ptr to convert this to a string. 119 120 HTable_Ptr : Exception_Data_Ptr; 121 -- Hash table pointer used to link entries together in the hash table 122 -- built (by Register_Exception in s-exctab.adb) for converting between 123 -- identities and names. 124 125 Foreign_Data : Address; 126 -- Data for imported exceptions. Not used in the Ada case. This 127 -- represents the address of the RTTI for the C++ case. 128 129 Raise_Hook : Raise_Action; 130 -- This field can be used to place a "hook" on an exception. If the 131 -- value is non-null, then it points to a procedure which is called 132 -- whenever the exception is raised. This call occurs immediately, 133 -- before any other actions taken by the raise (and in particular 134 -- before any unwinding of the stack occurs). 135 end record; 136 137 -- Definitions for standard predefined exceptions defined in Standard, 138 139 -- Why are the NULs necessary here, seems like they should not be 140 -- required, since Gigi is supposed to add a Nul to each name ??? 141 142 Constraint_Error_Name : constant String := "CONSTRAINT_ERROR" & ASCII.NUL; 143 Program_Error_Name : constant String := "PROGRAM_ERROR" & ASCII.NUL; 144 Storage_Error_Name : constant String := "STORAGE_ERROR" & ASCII.NUL; 145 Tasking_Error_Name : constant String := "TASKING_ERROR" & ASCII.NUL; 146 Abort_Signal_Name : constant String := "_ABORT_SIGNAL" & ASCII.NUL; 147 148 Numeric_Error_Name : constant String := "NUMERIC_ERROR" & ASCII.NUL; 149 -- This is used only in the Ada 83 case, but it is not worth having a 150 -- separate version of s-stalib.ads for use in Ada 83 mode. 151 152 Constraint_Error_Def : aliased Exception_Data := 153 (Not_Handled_By_Others => False, 154 Lang => 'A', 155 Name_Length => Constraint_Error_Name'Length, 156 Full_Name => Constraint_Error_Name'Address, 157 HTable_Ptr => null, 158 Foreign_Data => Null_Address, 159 Raise_Hook => null); 160 161 Numeric_Error_Def : aliased Exception_Data := 162 (Not_Handled_By_Others => False, 163 Lang => 'A', 164 Name_Length => Numeric_Error_Name'Length, 165 Full_Name => Numeric_Error_Name'Address, 166 HTable_Ptr => null, 167 Foreign_Data => Null_Address, 168 Raise_Hook => null); 169 170 Program_Error_Def : aliased Exception_Data := 171 (Not_Handled_By_Others => False, 172 Lang => 'A', 173 Name_Length => Program_Error_Name'Length, 174 Full_Name => Program_Error_Name'Address, 175 HTable_Ptr => null, 176 Foreign_Data => Null_Address, 177 Raise_Hook => null); 178 179 Storage_Error_Def : aliased Exception_Data := 180 (Not_Handled_By_Others => False, 181 Lang => 'A', 182 Name_Length => Storage_Error_Name'Length, 183 Full_Name => Storage_Error_Name'Address, 184 HTable_Ptr => null, 185 Foreign_Data => Null_Address, 186 Raise_Hook => null); 187 188 Tasking_Error_Def : aliased Exception_Data := 189 (Not_Handled_By_Others => False, 190 Lang => 'A', 191 Name_Length => Tasking_Error_Name'Length, 192 Full_Name => Tasking_Error_Name'Address, 193 HTable_Ptr => null, 194 Foreign_Data => Null_Address, 195 Raise_Hook => null); 196 197 Abort_Signal_Def : aliased Exception_Data := 198 (Not_Handled_By_Others => True, 199 Lang => 'A', 200 Name_Length => Abort_Signal_Name'Length, 201 Full_Name => Abort_Signal_Name'Address, 202 HTable_Ptr => null, 203 Foreign_Data => Null_Address, 204 Raise_Hook => null); 205 206 pragma Export (C, Constraint_Error_Def, "constraint_error"); 207 pragma Export (C, Numeric_Error_Def, "numeric_error"); 208 pragma Export (C, Program_Error_Def, "program_error"); 209 pragma Export (C, Storage_Error_Def, "storage_error"); 210 pragma Export (C, Tasking_Error_Def, "tasking_error"); 211 pragma Export (C, Abort_Signal_Def, "_abort_signal"); 212 213 Local_Partition_ID : Natural := 0; 214 -- This variable contains the local Partition_ID that will be used when 215 -- building exception occurrences. In distributed mode, it will be 216 -- set by each partition to the correct value during the elaboration. 217 218 type Exception_Trace_Kind is 219 (RM_Convention, 220 -- No particular trace is requested, only unhandled exceptions 221 -- in the environment task (following the RM) will be printed. 222 -- This is the default behavior. 223 224 Every_Raise, 225 -- Denotes the initial raise event for any exception occurrence, either 226 -- explicit or due to a specific language rule, within the context of a 227 -- task or not. 228 229 Unhandled_Raise, 230 -- Denotes the raise events corresponding to exceptions for which there 231 -- is no user defined handler. This includes unhandled exceptions in 232 -- task bodies. 233 234 Unhandled_Raise_In_Main 235 -- Same as Unhandled_Raise, except exceptions in task bodies are not 236 -- included. Same as RM_Convention, except (1) the message is printed as 237 -- soon as the environment task completes due to an unhandled exception 238 -- (before awaiting the termination of dependent tasks, and before 239 -- library-level finalization), and (2) a symbolic traceback is given 240 -- if possible. This is the default behavior if the binder switch -E is 241 -- used. 242 ); 243 -- Provide a way to denote different kinds of automatic traces related 244 -- to exceptions that can be requested. 245 246 Exception_Trace : Exception_Trace_Kind := RM_Convention; 247 pragma Atomic (Exception_Trace); 248 -- By default, follow the RM convention 249 250 ----------------- 251 -- Subprograms -- 252 ----------------- 253 254 procedure Abort_Undefer_Direct; 255 pragma Inline (Abort_Undefer_Direct); 256 -- A little procedure that just calls Abort_Undefer.all, for use in 257 -- clean up procedures, which only permit a simple subprogram name. 258 259 procedure Adafinal; 260 -- Performs the Ada Runtime finalization the first time it is invoked. 261 -- All subsequent calls are ignored. 262 263end System.Standard_Library; 264