diff options
Diffstat (limited to 'gcc-4.8.3/gcc/ada/a-except.ads')
| -rw-r--r-- | gcc-4.8.3/gcc/ada/a-except.ads | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/ada/a-except.ads b/gcc-4.8.3/gcc/ada/a-except.ads new file mode 100644 index 000000000..e395cf4f3 --- /dev/null +++ b/gcc-4.8.3/gcc/ada/a-except.ads @@ -0,0 +1,320 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- A D A . E X C E P T I O N S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2012, 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 -- +-- 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. -- +-- -- +------------------------------------------------------------------------------ + +-- This version of Ada.Exceptions is a full Ada 95 version. It omits Ada 2005 +-- features such as the additional definitions of Exception_Name returning +-- Wide_[Wide_]String. It differs from the Ada 95 version only in that it is +-- declared Preelaborate (see declaration below for why this is done). + +-- It is used for building the compiler and the basic tools, since these +-- builds may be done with bootstrap compilers that cannot handle these +-- additions. The full version of Ada.Exceptions can be found in the files +-- a-except-2005.ads/adb, and is used for all other builds where full Ada +-- 2005 functionality is required. In particular, it is used for building +-- run times on all targets. + +pragma Compiler_Unit; + +pragma Polling (Off); +-- We must turn polling off for this unit, because otherwise we get +-- elaboration circularities with ourself. + +with System; +with System.Parameters; +with System.Standard_Library; +with System.Traceback_Entries; + +package Ada.Exceptions is + pragma Preelaborate; + -- We make this preelaborable. If we did not do this, then run time units + -- used by the compiler (e.g. s-soflin.ads) would run into trouble. + -- Conformance with Ada 95 is not an issue, since this version is used + -- only by the compiler. + + type Exception_Id is private; + + Null_Id : constant Exception_Id; + + type Exception_Occurrence is limited private; + + type Exception_Occurrence_Access is access all Exception_Occurrence; + + Null_Occurrence : constant Exception_Occurrence; + + function Exception_Name (X : Exception_Occurrence) return String; + -- Same as Exception_Name (Exception_Identity (X)) + + function Exception_Name (Id : Exception_Id) return String; + + 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; + +private + 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 Current_Target_Exception return Exception_Occurrence; + pragma Export + (Ada, Current_Target_Exception, + "__gnat_current_target_exception"); + -- This routine should return the current raised exception on targets + -- which have built-in exception handling such as the Java Virtual + -- Machine. For other targets this routine is simply ignored. Currently, + -- only JGNAT uses this. See 4jexcept.ads for details. The pragma Export + -- allows this routine to be accessed elsewhere in the run-time, even + -- though it is in the private part of this package (it is not allowed + -- to be in the visible part, since this is set by the reference manual). + + 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. + + procedure Raise_From_Signal_Handler + (E : Exception_Id; + M : System.Address); + pragma Export + (Ada, Raise_From_Signal_Handler, + "ada__exceptions__raise_from_signal_handler"); + pragma No_Return (Raise_From_Signal_Handler); + -- This routine is used to raise an exception from a signal handler. The + -- signal handler has already stored the machine state (i.e. the state that + -- corresponds to the location at which the signal was raised). E is the + -- Exception_Id specifying what exception is being raised, and M is a + -- pointer to a null-terminated string which is the message to be raised. + -- Note that this routine never returns, so it is permissible to simply + -- jump to this routine, rather than call it. This may be appropriate for + -- systems where the right way to get out of signal handler is to alter the + -- PC value in the machine state or in some other way ask the operating + -- system to return here rather than to the original location. + + procedure Raise_From_Controlled_Operation + (X : Ada.Exceptions.Exception_Occurrence); + pragma No_Return (Raise_From_Controlled_Operation); + pragma Export + (Ada, Raise_From_Controlled_Operation, + "__gnat_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, + "__gnat_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. + + ----------------------- + -- Polling Interface -- + ----------------------- + + -- The GNAT compiler has an option to generate polling calls to the Poll + -- routine in this package. Specifying the -gnatP option for a compilation + -- causes a call to Ada.Exceptions.Poll to be generated on every subprogram + -- entry and on every iteration of a loop, thus avoiding the possibility of + -- a case of unbounded time between calls. + + -- This polling interface may be used for instrumentation or debugging + -- purposes (e.g. implementing watchpoints in software or in the debugger). + + -- In the GNAT technology itself, this interface is used to implement + -- immediate asynchronous transfer of control and immediate abort on + -- targets which do not provide for one thread interrupting another. + + -- Note: this used to be in a separate unit called System.Poll, but that + -- caused horrible circular elaboration problems between System.Poll and + -- Ada.Exceptions. One way of solving such circularities is unification! + + procedure Poll; + -- Check for asynchronous abort. Note that we do not inline the body. + -- This makes the interface more useful for debugging purposes. + + -------------------------- + -- Exception_Occurrence -- + -------------------------- + + package TBE renames System.Traceback_Entries; + + Max_Tracebacks : constant := 50; + -- Maximum number of trace backs stored in exception occurrence + + type Tracebacks_Array is array (1 .. Max_Tracebacks) of TBE.Traceback_Entry; + -- Traceback array stored in exception occurrence + + type Exception_Occurrence is record + Id : Exception_Id; + -- Exception_Identity for this exception occurrence + + 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 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 + + Null_Occurrence : constant Exception_Occurrence := ( + Id => null, + Msg_Length => 0, + Msg => (others => ' '), + Exception_Raised => False, + Pid => 0, + Num_Tracebacks => 0, + Tracebacks => (others => TBE.Null_TB_Entry)); + +end Ada.Exceptions; |