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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- G N A T . T R A C E B A C K . S Y M B O L I C --
-- --
-- B o d y --
-- --
-- Copyright (C) 1999-2010, 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. --
-- --
------------------------------------------------------------------------------
-- Run-time symbolic traceback support
with System.Soft_Links;
with Ada.Exceptions.Traceback; use Ada.Exceptions.Traceback;
package body GNAT.Traceback.Symbolic is
pragma Linker_Options ("-laddr2line");
pragma Linker_Options ("-lbfd");
pragma Linker_Options ("-liberty");
package TSL renames System.Soft_Links;
-- To perform the raw addresses to symbolic form translation we rely on a
-- libaddr2line symbolizer which examines debug info from a provided
-- executable file name, and an absolute path is needed to ensure the file
-- is always found. This is "__gnat_locate_exec_on_path (gnat_argv [0])"
-- for our executable file, a fairly heavy operation so we cache the
-- result.
Exename : System.Address;
-- Pointer to the name of the executable file to be used on all
-- invocations of the libaddr2line symbolization service.
Exename_Resolved : Boolean := False;
-- Flag to indicate whether we have performed the executable file name
-- resolution already. Relying on a not null Exename for this purpose
-- would be potentially inefficient as this is what we will get if the
-- resolution attempt fails.
------------------------
-- Symbolic_Traceback --
------------------------
function Symbolic_Traceback (Traceback : Tracebacks_Array) return String is
procedure convert_addresses
(filename : System.Address;
addrs : System.Address;
n_addrs : Integer;
buf : System.Address;
len : System.Address);
pragma Import (C, convert_addresses, "convert_addresses");
-- This is the procedure version of the Ada-aware addr2line. It places
-- in BUF a string representing the symbolic translation of the N_ADDRS
-- raw addresses provided in ADDRS, looked up in debug information from
-- FILENAME. LEN points to an integer which contains the size of the
-- BUF buffer at input and the result length at output.
--
-- This procedure is provided by libaddr2line on targets that support
-- it. A dummy version is in adaint.c for other targets so that build
-- of shared libraries doesn't generate unresolved symbols.
--
-- Note that this procedure is *not* thread-safe.
type Argv_Array is array (0 .. 0) of System.Address;
gnat_argv : access Argv_Array;
pragma Import (C, gnat_argv, "gnat_argv");
function locate_exec_on_path
(c_exename : System.Address) return System.Address;
pragma Import (C, locate_exec_on_path, "__gnat_locate_exec_on_path");
Res : String (1 .. 256 * Traceback'Length);
Len : Integer;
use type System.Address;
begin
-- The symbolic translation of an empty set of addresses is an empty
-- string.
if Traceback'Length = 0 then
return "";
end if;
-- If our input set of raw addresses is not empty, resort to the
-- libaddr2line service to symbolize it all.
-- Compute, cache and provide the absolute path to our executable file
-- name as the binary file where the relevant debug information is to be
-- found. If the executable file name resolution fails, we have no
-- sensible basis to invoke the symbolizer at all.
-- Protect all this against concurrent accesses explicitly, as the
-- underlying services are potentially thread unsafe.
TSL.Lock_Task.all;
if not Exename_Resolved then
Exename := locate_exec_on_path (gnat_argv (0));
Exename_Resolved := True;
end if;
if Exename /= System.Null_Address then
Len := Res'Length;
convert_addresses
(Exename, Traceback'Address, Traceback'Length,
Res (1)'Address, Len'Address);
end if;
TSL.Unlock_Task.all;
-- Return what the addr2line symbolizer has produced if we have called
-- it (the executable name resolution succeeded), or an empty string
-- otherwise.
if Exename /= System.Null_Address then
return Res (1 .. Len);
else
return "";
end if;
end Symbolic_Traceback;
function Symbolic_Traceback (E : Exception_Occurrence) return String is
begin
return Symbolic_Traceback (Tracebacks (E));
end Symbolic_Traceback;
end GNAT.Traceback.Symbolic;
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