1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . S T A N D A R D _ L I B R A R Y --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
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. --
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. --
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/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
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, an in both cases
37 -- the binder is not aware of such references.
39 -- System.Standard_Library also includes data that must be present in every
40 -- program, in particular the definitions of all the standard and also some
41 -- subprograms that must be present in every program.
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.
47 pragma Warnings (Off);
52 -- We must turn polling off for this unit, because otherwise we get
53 -- elaboration circularities with Ada.Exceptions if polling is on.
56 with Ada.Unchecked_Conversion;
58 package System.Standard_Library is
59 pragma Warnings (Off);
60 pragma Preelaborate_05;
63 type Big_String_Ptr is access all String (Positive);
64 for Big_String_Ptr'Storage_Size use 0;
65 -- A non-fat pointer type for null terminated strings
68 new Ada.Unchecked_Conversion (System.Address, Big_String_Ptr);
70 ---------------------------------------------
71 -- Type For Enumeration Image Index Tables --
72 ---------------------------------------------
74 -- Note: these types are declared at the start of this unit, since
75 -- they must appear before any enumeration types declared in this
76 -- unit. Note that the spec of system is already elaborated at
77 -- this point (since we are a child of system), which means that
78 -- enumeration types in package System cannot use these types.
80 type Image_Index_Table_8 is
81 array (Integer range <>) of Short_Short_Integer;
82 type Image_Index_Table_16 is
83 array (Integer range <>) of Short_Integer;
84 type Image_Index_Table_32 is
85 array (Integer range <>) of Integer;
86 -- These types are used to generate the index vector used for enumeration
87 -- type image tables. See spec of Exp_Imgv in the main GNAT sources for a
88 -- full description of the data structures that are used here.
90 -------------------------------------
91 -- Exception Declarations and Data --
92 -------------------------------------
94 type Raise_Action is access procedure;
95 -- A pointer to a procedure used in the Raise_Hook field
98 type Exception_Data_Ptr is access all Exception_Data;
99 -- An equivalent of Exception_Id that is public
101 type Exception_Code is mod 2 ** Integer'Size;
102 -- A scalar value bound to some exception data. Typically used for
103 -- imported or exported exceptions on VMS. Having a separate type for this
104 -- is useful to enforce consistency throughout the various run-time units
105 -- handling such codes, and having it unsigned is the most appropriate
106 -- choice for it's currently single use on VMS.
108 -- ??? The construction in Cstand has no way to access the proper type
109 -- node for Exception_Code, and currently uses Standard_Unsigned as a
110 -- fallback. The representations shall match, and the size clause below
111 -- is aimed at ensuring that.
113 for Exception_Code'Size use Integer'Size;
115 -- The following record defines the underlying representation of exceptions
117 -- WARNING! Any changes to this may need to be reflected in the following
118 -- locations in the compiler and runtime code:
120 -- 1. The Internal_Exception routine in s-exctab.adb
121 -- 2. The processing in gigi that tests Not_Handled_By_Others
122 -- 3. Expand_N_Exception_Declaration in Exp_Ch11
123 -- 4. The construction of the exception type in Cstand
125 type Exception_Data is record
126 Not_Handled_By_Others : Boolean;
127 -- Normally set False, indicating that the exception is handled in the
128 -- usual way by others (i.e. an others handler handles the exception).
129 -- Set True to indicate that this exception is not caught by others
130 -- handlers, but must be explicitly named in a handler. This latter
131 -- setting is currently used by the Abort_Signal.
134 -- A character indicating the language raising the exception.
135 -- Set to "A" for exceptions defined by an Ada program.
136 -- Set to "V" for imported VMS exceptions.
138 Name_Length : Natural;
139 -- Length of fully expanded name of exception
141 Full_Name : System.Address;
142 -- Fully expanded name of exception, null terminated
143 -- You can use To_Ptr to convert this to a string.
145 HTable_Ptr : Exception_Data_Ptr;
146 -- Hash table pointer used to link entries together in the hash table
147 -- built (by Register_Exception in s-exctab.adb) for converting between
148 -- identities and names.
150 Import_Code : Exception_Code;
151 -- Value for imported exceptions. Needed only for the handling of
152 -- Import/Export_Exception for the VMS case, but present in all
153 -- implementations (we might well extend this mechanism for other
154 -- systems in the future).
156 Raise_Hook : Raise_Action;
157 -- This field can be used to place a "hook" on an exception. If the
158 -- value is non-null, then it points to a procedure which is called
159 -- whenever the exception is raised. This call occurs immediately,
160 -- before any other actions taken by the raise (and in particular
161 -- before any unwinding of the stack occurs).
164 -- Definitions for standard predefined exceptions defined in Standard,
166 -- Why are the NULs necessary here, seems like they should not be
167 -- required, since Gigi is supposed to add a Nul to each name ???
169 Constraint_Error_Name : constant String := "CONSTRAINT_ERROR" & ASCII.NUL;
170 Program_Error_Name : constant String := "PROGRAM_ERROR" & ASCII.NUL;
171 Storage_Error_Name : constant String := "STORAGE_ERROR" & ASCII.NUL;
172 Tasking_Error_Name : constant String := "TASKING_ERROR" & ASCII.NUL;
173 Abort_Signal_Name : constant String := "_ABORT_SIGNAL" & ASCII.NUL;
175 Numeric_Error_Name : constant String := "NUMERIC_ERROR" & ASCII.NUL;
176 -- This is used only in the Ada 83 case, but it is not worth having a
177 -- separate version of s-stalib.ads for use in Ada 83 mode.
179 Constraint_Error_Def : aliased Exception_Data :=
180 (Not_Handled_By_Others => False,
182 Name_Length => Constraint_Error_Name'Length,
183 Full_Name => Constraint_Error_Name'Address,
188 Numeric_Error_Def : aliased Exception_Data :=
189 (Not_Handled_By_Others => False,
191 Name_Length => Numeric_Error_Name'Length,
192 Full_Name => Numeric_Error_Name'Address,
197 Program_Error_Def : aliased Exception_Data :=
198 (Not_Handled_By_Others => False,
200 Name_Length => Program_Error_Name'Length,
201 Full_Name => Program_Error_Name'Address,
206 Storage_Error_Def : aliased Exception_Data :=
207 (Not_Handled_By_Others => False,
209 Name_Length => Storage_Error_Name'Length,
210 Full_Name => Storage_Error_Name'Address,
215 Tasking_Error_Def : aliased Exception_Data :=
216 (Not_Handled_By_Others => False,
218 Name_Length => Tasking_Error_Name'Length,
219 Full_Name => Tasking_Error_Name'Address,
224 Abort_Signal_Def : aliased Exception_Data :=
225 (Not_Handled_By_Others => True,
227 Name_Length => Abort_Signal_Name'Length,
228 Full_Name => Abort_Signal_Name'Address,
233 pragma Export (C, Constraint_Error_Def, "constraint_error");
234 pragma Export (C, Numeric_Error_Def, "numeric_error");
235 pragma Export (C, Program_Error_Def, "program_error");
236 pragma Export (C, Storage_Error_Def, "storage_error");
237 pragma Export (C, Tasking_Error_Def, "tasking_error");
238 pragma Export (C, Abort_Signal_Def, "_abort_signal");
240 Local_Partition_ID : Natural := 0;
241 -- This variable contains the local Partition_ID that will be used when
242 -- building exception occurrences. In distributed mode, it will be
243 -- set by each partition to the correct value during the elaboration.
245 type Exception_Trace_Kind is
247 -- No particular trace is requested, only unhandled exceptions
248 -- in the environment task (following the RM) will be printed.
249 -- This is the default behavior.
252 -- Denotes every possible raise event, either explicit or due to
253 -- a specific language rule, within the context of a task or not.
256 -- Denotes the raise events corresponding to exceptions for which
257 -- there is no user defined handler.
259 -- Provide a way to denote different kinds of automatic traces related
260 -- to exceptions that can be requested.
262 Exception_Trace : Exception_Trace_Kind := RM_Convention;
263 pragma Atomic (Exception_Trace);
264 -- By default, follow the RM convention
270 procedure Abort_Undefer_Direct;
271 pragma Inline (Abort_Undefer_Direct);
272 -- A little procedure that just calls Abort_Undefer.all, for use in
273 -- clean up procedures, which only permit a simple subprogram name.
276 -- Performs the Ada Runtime finalization the first time it is invoked.
277 -- All subsequent calls are ignored.
279 end System.Standard_Library;