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) 1992-2020, 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 49with Ada.Unchecked_Conversion; 50 51package System.Standard_Library is 52 53 -- Historical note: pragma Preelaborate was surrounded by a pair of pragma 54 -- Warnings (Off/On) to circumvent a bootstrap issue. 55 56 pragma Preelaborate; 57 58 subtype Big_String is String (1 .. Positive'Last); 59 pragma Suppress_Initialization (Big_String); 60 -- Type used to obtain string access to given address. Initialization is 61 -- suppressed, since we never want to have variables of this type, and 62 -- we never want to attempt initialiazation of virtual variables of this 63 -- type (e.g. when pragma Normalize_Scalars is used). 64 65 type Big_String_Ptr is access all Big_String; 66 for Big_String_Ptr'Storage_Size use 0; 67 -- We use this access type to pass a pointer to an area of storage to be 68 -- accessed as a string. Of course when this pointer is used, it is the 69 -- responsibility of the accessor to ensure proper bounds. The storage 70 -- size clause ensures we do not allocate variables of this type. 71 72 function To_Ptr is 73 new Ada.Unchecked_Conversion (System.Address, Big_String_Ptr); 74 75 ------------------------------------- 76 -- Exception Declarations and Data -- 77 ------------------------------------- 78 79 type Raise_Action is access procedure; 80 pragma Favor_Top_Level (Raise_Action); 81 -- A pointer to a procedure used in the Raise_Hook field 82 83 type Exception_Data; 84 type Exception_Data_Ptr is access all Exception_Data; 85 -- An equivalent of Exception_Id that is public 86 87 -- The following record defines the underlying representation of exceptions 88 89 -- WARNING: Any changes to this may need to be reflected in the following 90 -- locations in the compiler and runtime code: 91 92 -- 1. The Internal_Exception routine in s-exctab.adb 93 -- 2. The processing in gigi that tests Not_Handled_By_Others 94 -- 3. Expand_N_Exception_Declaration in Exp_Ch11 95 -- 4. The construction of the exception type in Cstand 96 97 type Exception_Data is record 98 Not_Handled_By_Others : Boolean; 99 -- Normally set False, indicating that the exception is handled in the 100 -- usual way by others (i.e. an others handler handles the exception). 101 -- Set True to indicate that this exception is not caught by others 102 -- handlers, but must be explicitly named in a handler. This latter 103 -- setting is currently used by the Abort_Signal. 104 105 Lang : Character; 106 -- A character indicating the language raising the exception. 107 -- Set to "A" for exceptions defined by an Ada program. 108 -- Set to "C" for imported C++ exceptions. 109 110 Name_Length : Natural; 111 -- Length of fully expanded name of exception 112 113 Full_Name : System.Address; 114 -- Fully expanded name of exception, null terminated 115 -- You can use To_Ptr to convert this to a string. 116 117 HTable_Ptr : Exception_Data_Ptr; 118 -- Hash table pointer used to link entries together in the hash table 119 -- built (by Register_Exception in s-exctab.adb) for converting between 120 -- identities and names. 121 122 Foreign_Data : Address; 123 -- Data for imported exceptions. Not used in the Ada case. This 124 -- represents the address of the RTTI for the C++ case. 125 126 Raise_Hook : Raise_Action; 127 -- This field can be used to place a "hook" on an exception. If the 128 -- value is non-null, then it points to a procedure which is called 129 -- whenever the exception is raised. This call occurs immediately, 130 -- before any other actions taken by the raise (and in particular 131 -- before any unwinding of the stack occurs). 132 end record; 133 134 -- Definitions for standard predefined exceptions defined in Standard, 135 136 -- Why are the NULs necessary here, seems like they should not be 137 -- required, since Gigi is supposed to add a Nul to each name ??? 138 139 Constraint_Error_Name : constant String := "CONSTRAINT_ERROR" & ASCII.NUL; 140 Program_Error_Name : constant String := "PROGRAM_ERROR" & ASCII.NUL; 141 Storage_Error_Name : constant String := "STORAGE_ERROR" & ASCII.NUL; 142 Tasking_Error_Name : constant String := "TASKING_ERROR" & ASCII.NUL; 143 Abort_Signal_Name : constant String := "_ABORT_SIGNAL" & ASCII.NUL; 144 145 Numeric_Error_Name : constant String := "NUMERIC_ERROR" & ASCII.NUL; 146 -- This is used only in the Ada 83 case, but it is not worth having a 147 -- separate version of s-stalib.ads for use in Ada 83 mode. 148 149 Constraint_Error_Def : aliased Exception_Data := 150 (Not_Handled_By_Others => False, 151 Lang => 'A', 152 Name_Length => Constraint_Error_Name'Length, 153 Full_Name => Constraint_Error_Name'Address, 154 HTable_Ptr => null, 155 Foreign_Data => Null_Address, 156 Raise_Hook => null); 157 158 Numeric_Error_Def : aliased Exception_Data := 159 (Not_Handled_By_Others => False, 160 Lang => 'A', 161 Name_Length => Numeric_Error_Name'Length, 162 Full_Name => Numeric_Error_Name'Address, 163 HTable_Ptr => null, 164 Foreign_Data => Null_Address, 165 Raise_Hook => null); 166 167 Program_Error_Def : aliased Exception_Data := 168 (Not_Handled_By_Others => False, 169 Lang => 'A', 170 Name_Length => Program_Error_Name'Length, 171 Full_Name => Program_Error_Name'Address, 172 HTable_Ptr => null, 173 Foreign_Data => Null_Address, 174 Raise_Hook => null); 175 176 Storage_Error_Def : aliased Exception_Data := 177 (Not_Handled_By_Others => False, 178 Lang => 'A', 179 Name_Length => Storage_Error_Name'Length, 180 Full_Name => Storage_Error_Name'Address, 181 HTable_Ptr => null, 182 Foreign_Data => Null_Address, 183 Raise_Hook => null); 184 185 Tasking_Error_Def : aliased Exception_Data := 186 (Not_Handled_By_Others => False, 187 Lang => 'A', 188 Name_Length => Tasking_Error_Name'Length, 189 Full_Name => Tasking_Error_Name'Address, 190 HTable_Ptr => null, 191 Foreign_Data => Null_Address, 192 Raise_Hook => null); 193 194 Abort_Signal_Def : aliased Exception_Data := 195 (Not_Handled_By_Others => True, 196 Lang => 'A', 197 Name_Length => Abort_Signal_Name'Length, 198 Full_Name => Abort_Signal_Name'Address, 199 HTable_Ptr => null, 200 Foreign_Data => Null_Address, 201 Raise_Hook => null); 202 203 pragma Export (C, Constraint_Error_Def, "constraint_error"); 204 pragma Export (C, Numeric_Error_Def, "numeric_error"); 205 pragma Export (C, Program_Error_Def, "program_error"); 206 pragma Export (C, Storage_Error_Def, "storage_error"); 207 pragma Export (C, Tasking_Error_Def, "tasking_error"); 208 pragma Export (C, Abort_Signal_Def, "_abort_signal"); 209 210 Local_Partition_ID : Natural := 0; 211 -- This variable contains the local Partition_ID that will be used when 212 -- building exception occurrences. In distributed mode, it will be 213 -- set by each partition to the correct value during the elaboration. 214 215 type Exception_Trace_Kind is 216 (RM_Convention, 217 -- No particular trace is requested, only unhandled exceptions 218 -- in the environment task (following the RM) will be printed. 219 -- This is the default behavior. 220 221 Every_Raise, 222 -- Denotes the initial raise event for any exception occurrence, either 223 -- explicit or due to a specific language rule, within the context of a 224 -- task or not. 225 226 Unhandled_Raise, 227 -- Denotes the raise events corresponding to exceptions for which there 228 -- is no user defined handler. This includes unhandled exceptions in 229 -- task bodies. 230 231 Unhandled_Raise_In_Main 232 -- Same as Unhandled_Raise, except exceptions in task bodies are not 233 -- included. Same as RM_Convention, except (1) the message is printed as 234 -- soon as the environment task completes due to an unhandled exception 235 -- (before awaiting the termination of dependent tasks, and before 236 -- library-level finalization), and (2) a symbolic traceback is given 237 -- if possible. This is the default behavior if the binder switch -E is 238 -- used. 239 ); 240 -- Provide a way to denote different kinds of automatic traces related 241 -- to exceptions that can be requested. 242 243 Exception_Trace : Exception_Trace_Kind := RM_Convention; 244 pragma Atomic (Exception_Trace); 245 -- By default, follow the RM convention 246 247 ----------------- 248 -- Subprograms -- 249 ----------------- 250 251 procedure Abort_Undefer_Direct; 252 pragma Inline (Abort_Undefer_Direct); 253 -- A little procedure that just calls Abort_Undefer.all, for use in 254 -- clean up procedures, which only permit a simple subprogram name. 255 256 procedure Adafinal; 257 -- Performs the Ada Runtime finalization the first time it is invoked. 258 -- All subsequent calls are ignored. 259 260end System.Standard_Library; 261