1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- S Y S T E M . E X C E P T I O N _ T R A C E S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2000-2019, AdaCore -- 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 provides an interface allowing to control *automatic* output 33-- to standard error upon exception occurrences (as opposed to explicit 34-- generation of traceback information using System.Traceback). 35 36-- This output includes the basic information associated with the exception 37-- (name, message) as well as a backtrace of the call chain at the point 38-- where the exception occurred. This backtrace is only output if the call 39-- chain information is available, depending if the binder switch dedicated 40-- to that purpose has been used or not. 41 42-- The default backtrace is in the form of absolute code locations which may 43-- be converted to corresponding source locations using the addr2line utility 44-- or from within GDB. Please refer to System.Traceback for information about 45-- what is necessary to be able to exploit this possibility. 46 47-- The backtrace output can also be customized by way of a "decorator" which 48-- may return any string output in association with a provided call chain. 49-- The decorator replaces the default backtrace mentioned above. 50 51-- On systems that use DWARF debugging output, then if the "-g" compiler 52-- switch and the "-Es" binder switch are used, the decorator is automatically 53-- set to Symbolic_Traceback. 54 55with System.Traceback_Entries; 56 57package System.Exception_Traces is 58 59 -- The following defines the exact situations in which raises will 60 -- cause automatic output of trace information. 61 62 type Trace_Kind is 63 (Every_Raise, 64 -- Denotes the initial raise event for any exception occurrence, either 65 -- explicit or due to a specific language rule, within the context of a 66 -- task or not. 67 68 Unhandled_Raise, 69 -- Denotes the raise events corresponding to exceptions for which there 70 -- is no user defined handler. This includes unhandled exceptions in 71 -- task bodies. 72 73 Unhandled_Raise_In_Main 74 -- Same as Unhandled_Raise, except exceptions in task bodies are not 75 -- included. 76 ); 77 78 -- The following procedures can be used to activate and deactivate 79 -- traces identified by the above trace kind values. 80 81 procedure Trace_On (Kind : Trace_Kind); 82 -- Activate the traces denoted by Kind 83 84 procedure Trace_Off; 85 -- Stop the tracing requested by the last call to Trace_On. 86 -- Has no effect if no such call has ever occurred. 87 88 -- The following provide the backtrace decorating facilities 89 90 type Traceback_Decorator is access 91 function (Traceback : Traceback_Entries.Tracebacks_Array) return String; 92 -- A backtrace decorator is a function which returns the string to be 93 -- output for a call chain provided by way of a tracebacks array. 94 95 procedure Set_Trace_Decorator (Decorator : Traceback_Decorator); 96 -- Set the decorator to be used for future automatic outputs. Restore the 97 -- default behavior if the provided access value is null. 98 -- 99 -- Note: System.Traceback.Symbolic.Symbolic_Traceback may be used as the 100 -- Decorator, to get a symbolic traceback. This will cause a significant 101 -- cpu and memory overhead on some platforms. 102 -- 103 -- Note: The Decorator is called when constructing the 104 -- Exception_Information; that needs to be taken into account 105 -- if the Decorator has any side effects. 106 107end System.Exception_Traces; 108