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-- --
-- --
-- A D A . E X C E P T I O N S --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the contents of the part following the private keyword. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
-- This is the default version of this package. We also have cert and zfp
-- versions.
with System;
with System.Parameters;
with System.Standard_Library;
with System.Traceback_Entries;
package Ada.Exceptions is
pragma Preelaborate;
-- In accordance with Ada 2005 AI-362.
type Exception_Id is private;
pragma Preelaborable_Initialization (Exception_Id);
Null_Id : constant Exception_Id;
type Exception_Occurrence is limited private;
pragma Preelaborable_Initialization (Exception_Occurrence);
type Exception_Occurrence_Access is access all Exception_Occurrence;
Null_Occurrence : constant Exception_Occurrence;
function Exception_Name (Id : Exception_Id) return String;
function Exception_Name (X : Exception_Occurrence) return String;
function Wide_Exception_Name
(Id : Exception_Id) return Wide_String;
pragma Ada_05 (Wide_Exception_Name);
function Wide_Exception_Name
(X : Exception_Occurrence) return Wide_String;
pragma Ada_05 (Wide_Exception_Name);
function Wide_Wide_Exception_Name
(Id : Exception_Id) return Wide_Wide_String;
pragma Ada_05 (Wide_Wide_Exception_Name);
function Wide_Wide_Exception_Name
(X : Exception_Occurrence) return Wide_Wide_String;
pragma Ada_05 (Wide_Wide_Exception_Name);
procedure Raise_Exception (E : Exception_Id; Message : String := "");
pragma No_Return (Raise_Exception);
-- Note: In accordance with AI-466, CE is raised if E = Null_Id
function Exception_Message (X : Exception_Occurrence) return String;
procedure Reraise_Occurrence (X : Exception_Occurrence);
-- Note: it would be really nice to give a pragma No_Return for this
-- procedure, but it would be wrong, since Reraise_Occurrence does return
-- if the argument is the null exception occurrence. See also procedure
-- Reraise_Occurrence_Always in the private part of this package.
function Exception_Identity (X : Exception_Occurrence) return Exception_Id;
function Exception_Information (X : Exception_Occurrence) return String;
-- The format of the exception information is as follows:
-- exception name (as in Exception_Name)
-- message (or a null line if no message)
-- PID=nnnn
-- 0xyyyyyyyy 0xyyyyyyyy ...
-- The lines are separated by a ASCII.LF character
-- The nnnn is the partition Id given as decimal digits
-- The 0x... line represents traceback program counter locations,
-- in order with the first one being the exception location.
-- Note on ordering: the compiler uses the Save_Occurrence procedure, but
-- not the function from Rtsfind, so it is important that the procedure
-- come first, since Rtsfind finds the first matching entity.
procedure Save_Occurrence
(Target : out Exception_Occurrence;
Source : Exception_Occurrence);
function Save_Occurrence
(Source : Exception_Occurrence)
return Exception_Occurrence_Access;
-- Ada 2005 (AI-438): The language revision introduces the following
-- subprograms and attribute definitions. We do not provide them
-- explicitly. instead, the corresponding stream attributes are made
-- available through a pragma Stream_Convert in the private part.
-- procedure Read_Exception_Occurrence
-- (Stream : not null access Ada.Streams.Root_Stream_Type'Class;
-- Item : out Exception_Occurrence);
-- procedure Write_Exception_Occurrence
-- (Stream : not null access Ada.Streams.Root_Stream_Type'Class;
-- Item : Exception_Occurrence);
-- for Exception_Occurrence'Read use Read_Exception_Occurrence;
-- for Exception_Occurrence'Write use Write_Exception_Occurrence;
package SSL renames System.Standard_Library;
package SP renames System.Parameters;
subtype EOA is Exception_Occurrence_Access;
Exception_Msg_Max_Length : constant := SP.Default_Exception_Msg_Max_Length;
-- Exception_Id --
subtype Code_Loc is System.Address;
-- Code location used in building exception tables and for call addresses
-- when propagating an exception. Values of this type are created by using
-- Label'Address or extracted from machine states using Get_Code_Loc.
Null_Loc : constant Code_Loc := System.Null_Address;
-- Null code location, used to flag outer level frame
type Exception_Id is new SSL.Exception_Data_Ptr;
function EId_To_String (X : Exception_Id) return String;
function String_To_EId (S : String) return Exception_Id;
pragma Stream_Convert (Exception_Id, String_To_EId, EId_To_String);
-- Functions for implementing Exception_Id stream attributes
Null_Id : constant Exception_Id := null;
-- Private Subprograms --
function Exception_Name_Simple (X : Exception_Occurrence) return String;
-- Like Exception_Name, but returns the simple non-qualified name of the
-- exception. This is used to implement the Exception_Name function in
-- Current_Exceptions (the DEC compatible unit). It is called from the
-- compiler generated code (using Rtsfind, which does not respect the
-- private barrier, so we can place this function in the private part
-- where the compiler can find it, but the spec is unchanged.)
procedure Raise_Exception_Always (E : Exception_Id; Message : String := "");
pragma No_Return (Raise_Exception_Always);
pragma Export (Ada, Raise_Exception_Always, "__gnat_raise_exception");
-- This differs from Raise_Exception only in that the caller has determined
-- that for sure the parameter E is not null, and that therefore no check
-- for Null_Id is required. The expander converts Raise_Exception calls to
-- Raise_Exception_Always if it can determine this is the case. The Export
-- allows this routine to be accessed from Pure units.
-- Make these callable from strub contexts.
pragma Machine_Attribute (Raise_Exception_Always,
"strub", "callable");
pragma Machine_Attribute (Raise_Exception,
"strub", "callable");
-- This property should arguably be visible to callers, but let's
-- keep it private for now. In practice, it doesn't matter, since
-- it's only checked in the back end.
procedure Raise_From_Controlled_Operation (X : Exception_Occurrence);
pragma No_Return (Raise_From_Controlled_Operation);
pragma Export
(Ada, Raise_From_Controlled_Operation,
-- Raise Program_Error, providing information about X (an exception raised
-- during a controlled operation) in the exception message.
procedure Reraise_Library_Exception_If_Any;
pragma Export
(Ada, Reraise_Library_Exception_If_Any,
-- If there was an exception raised during library-level finalization,
-- reraise the exception.
procedure Reraise_Occurrence_Always (X : Exception_Occurrence);
pragma No_Return (Reraise_Occurrence_Always);
-- This differs from Raise_Occurrence only in that the caller guarantees
-- that for sure the parameter X is not the null occurrence, and that
-- therefore this procedure cannot return. The expander uses this routine
-- in the translation of a raise statement with no parameter (reraise).
procedure Reraise_Occurrence_No_Defer (X : Exception_Occurrence);
pragma No_Return (Reraise_Occurrence_No_Defer);
-- Exactly like Reraise_Occurrence, except that abort is not deferred
-- before the call and the parameter X is known not to be the null
-- occurrence. This is used in generated code when it is known that abort
-- is already deferred.
function Triggered_By_Abort return Boolean;
-- Determine whether the current exception (if it exists) is an instance of
-- Standard'Abort_Signal.
-- Exception_Occurrence --
package TBE renames System.Traceback_Entries;
Max_Tracebacks : constant := 50;
-- Maximum number of trace backs stored in exception occurrence
subtype Tracebacks_Array is TBE.Tracebacks_Array (1 .. Max_Tracebacks);
-- Traceback array stored in exception occurrence
type Exception_Occurrence is record
Id : Exception_Id := Null_Id;
-- Exception_Identity for this exception occurrence
Machine_Occurrence : System.Address;
-- The underlying machine occurrence. For GCC, this corresponds to the
-- _Unwind_Exception structure address.
Msg_Length : Natural := 0;
-- Length of message (zero = no message)
Msg : String (1 .. Exception_Msg_Max_Length);
-- Characters of message
Exception_Raised : Boolean := False;
-- Set to true to indicate that this exception occurrence has actually
-- been raised. When an exception occurrence is first created, this is
-- set to False, then when it is processed by Raise_Current_Exception,
-- it is set to True. If Raise_Current_Exception is used to raise an
-- exception for which this flag is already True, then it knows that
-- it is dealing with the reraise case (which is useful to distinguish
-- for exception tracing purposes).
Pid : Natural := 0;
-- Partition_Id for partition raising exception
Num_Tracebacks : Natural range 0 .. Max_Tracebacks := 0;
-- Number of traceback entries stored
Tracebacks : Tracebacks_Array;
-- Stored tracebacks (in Tracebacks (1 .. Num_Tracebacks))
end record;
function "=" (Left, Right : Exception_Occurrence) return Boolean
is abstract;
-- Don't allow comparison on exception occurrences, we should not need
-- this, and it would not work right, because of the Msg and Tracebacks
-- fields which have unused entries not copied by Save_Occurrence.
function Get_Exception_Machine_Occurrence
(X : Exception_Occurrence) return System.Address;
pragma Export (Ada, Get_Exception_Machine_Occurrence,
-- Get the machine occurrence corresponding to an exception occurrence.
-- It is Null_Address if there is no machine occurrence (in runtimes that
-- doesn't use GCC mechanism) or if it has been lost (Save_Occurrence
-- doesn't save the machine occurrence).
function EO_To_String (X : Exception_Occurrence) return String;
function String_To_EO (S : String) return Exception_Occurrence;
pragma Stream_Convert (Exception_Occurrence, String_To_EO, EO_To_String);
-- Functions for implementing Exception_Occurrence stream attributes
pragma Warnings (Off, "aggregate not fully initialized");
Null_Occurrence : constant Exception_Occurrence := (others => <>);
pragma Warnings (On, "aggregate not fully initialized");
end Ada.Exceptions;