| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- G N A T . C P P _ E X C E P T I O N S -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2013, AdaCore -- |
| -- -- |
| -- 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 -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. -- |
| -- -- |
| -- 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 -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System; |
| with System.Storage_Elements; |
| with Interfaces.C; use Interfaces.C; |
| with Ada.Unchecked_Conversion; |
| with System.Standard_Library; use System.Standard_Library; |
| |
| package body GNAT.CPP_Exceptions is |
| |
| -- Note: all functions prefixed by __cxa are part of the c++ ABI for |
| -- exception handling. As they are provided by the c++ library, there |
| -- must be no dependencies on it in the compiled code of this unit, but |
| -- there can be dependencies in instances. This is required to be able |
| -- to build the shared library without the c++ library. |
| |
| function To_Exception_Data_Ptr is new |
| Ada.Unchecked_Conversion |
| (Exception_Id, Exception_Data_Ptr); |
| -- Convert an Exception_Id to its non-private type. This is used to get |
| -- the RTTI of a C++ exception |
| |
| function Get_Exception_Machine_Occurrence |
| (X : Exception_Occurrence) return System.Address; |
| pragma Import (Ada, Get_Exception_Machine_Occurrence, |
| "__gnat_get_exception_machine_occurrence"); |
| -- Imported function (from Ada.Exceptions) that returns the machine |
| -- occurrence from an exception occurrence. |
| |
| ------------------------- |
| -- Raise_Cpp_Exception -- |
| ------------------------- |
| |
| procedure Raise_Cpp_Exception (Id : Exception_Id; Value : T) |
| is |
| Id_Data : constant Exception_Data_Ptr := To_Exception_Data_Ptr (Id); |
| -- Get a non-private view on the exception |
| |
| type T_Acc is access all T; |
| pragma Convention (C, T_Acc); |
| -- Access type to the object compatible with C |
| |
| Occ : T_Acc; |
| -- The occurrence to propagate |
| |
| function cxa_allocate_exception (Size : size_t) return T_Acc; |
| pragma Import (C, cxa_allocate_exception, "__cxa_allocate_exception"); |
| -- The C++ function to allocate an occurrence |
| |
| procedure cxa_throw (Obj : T_Acc; Tinfo : System.Address; |
| Dest : System.Address); |
| pragma Import (C, cxa_throw, "__cxa_throw"); |
| pragma No_Return (cxa_throw); |
| -- The C++ function to raise an exception |
| begin |
| -- Check the exception was imported from C++ |
| |
| if Id_Data.Lang /= 'C' then |
| raise Constraint_Error; |
| end if; |
| |
| -- Allocate the C++ occurrence |
| |
| Occ := cxa_allocate_exception (T'Size / System.Storage_Unit); |
| |
| -- Set the object |
| |
| Occ.all := Value; |
| |
| -- Throw the exception |
| |
| cxa_throw (Occ, Id_Data.Foreign_Data, System.Null_Address); |
| end Raise_Cpp_Exception; |
| |
| ---------------- |
| -- Get_Object -- |
| ---------------- |
| |
| function Get_Object (X : Exception_Occurrence) return T |
| is |
| use System; |
| use System.Storage_Elements; |
| |
| Unwind_Exception_Size : Natural; |
| pragma Import (C, Unwind_Exception_Size, "__gnat_unwind_exception_size"); |
| -- Size in bytes of _Unwind_Exception |
| |
| Exception_Addr : constant Address := |
| Get_Exception_Machine_Occurrence (X); |
| -- Machine occurrence of X |
| |
| begin |
| -- Check the machine occurrence exists |
| |
| if Exception_Addr = Null_Address then |
| raise Constraint_Error; |
| end if; |
| |
| declare |
| -- Import the object from the occurrence |
| Result : T; |
| pragma Import (Ada, Result); |
| for Result'Address use |
| Exception_Addr + Storage_Offset (Unwind_Exception_Size); |
| begin |
| -- And return it |
| return Result; |
| end; |
| end Get_Object; |
| end GNAT.CPP_Exceptions; |
