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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . D W A R F _ L I N E S --
-- --
-- S p e c --
-- --
-- Copyright (C) 2009-2018, Free Software Foundation, Inc. --
-- --
-- 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 package provides routines to read DWARF line number information from
-- a generic object file with as little overhead as possible. This allows
-- conversions from PC addresses to human readable source locations.
--
-- Objects must be built with debugging information, however only the
-- .debug_line section of the object file is referenced. In cases where object
-- size is a consideration it's possible to strip all other .debug sections,
-- which will decrease the size of the object significantly.
pragma Polling (Off);
-- We must turn polling off for this unit, because otherwise we can get
-- elaboration circularities when polling is turned on
with Ada.Exceptions.Traceback;
with System.Object_Reader;
with System.Storage_Elements;
with System.Bounded_Strings;
package System.Dwarf_Lines is
package AET renames Ada.Exceptions.Traceback;
package SOR renames System.Object_Reader;
type Dwarf_Context (In_Exception : Boolean := False) is private;
-- Type encapsulation the state of the Dwarf reader. When In_Exception
-- is True we are parsing as part of a exception handler decorator, we do
-- not want an exception to be raised, the parsing is done safely skipping
-- DWARF file that cannot be read or with stripped debug section for
-- example.
procedure Open
(File_Name : String;
C : out Dwarf_Context;
Success : out Boolean);
procedure Close (C : in out Dwarf_Context);
-- Open and close files
procedure Set_Load_Address (C : in out Dwarf_Context; Addr : Address);
-- Set the load address of a file. This is used to rebase PIE (Position
-- Independant Executable) binaries.
function Is_Inside (C : Dwarf_Context; Addr : Address) return Boolean;
pragma Inline (Is_Inside);
-- Return true iff a run-time address Addr is within the module
function Low (C : Dwarf_Context) return Address;
pragma Inline (Low);
-- Return the lowest address of C, from the module object file
procedure Dump (C : in out Dwarf_Context);
-- Dump each row found in the object's .debug_lines section to standard out
procedure Dump_Cache (C : Dwarf_Context);
-- Dump the cache (if present)
procedure Enable_Cache (C : in out Dwarf_Context);
-- Read symbols information to speed up Symbolic_Traceback.
procedure Symbolic_Traceback
(Cin : Dwarf_Context;
Traceback : AET.Tracebacks_Array;
Suppress_Hex : Boolean;
Symbol_Found : in out Boolean;
Res : in out System.Bounded_Strings.Bounded_String);
-- Generate a string for a traceback suitable for displaying to the user.
-- If one or more symbols are found, Symbol_Found is set to True. This
-- allows the caller to fall back to hexadecimal addresses.
Dwarf_Error : exception;
-- Raised if a problem is encountered parsing DWARF information. Can be a
-- result of a logic error or malformed DWARF information.
private
-- The following section numbers reference
-- "DWARF Debugging Information Format, Version 3"
-- published by the Standards Group, http://freestandards.org.
-- 6.2.2 State Machine Registers
type Line_Info_Registers is record
Address : SOR.uint64;
File : SOR.uint32;
Line : SOR.uint32;
Column : SOR.uint32;
Is_Stmt : Boolean;
Basic_Block : Boolean;
End_Sequence : Boolean;
Prologue_End : Boolean;
Epilogue_Begin : Boolean;
ISA : SOR.uint32;
Is_Row : Boolean;
end record;
-- 6.2.4 The Line Number Program Prologue
MAX_OPCODE_LENGTHS : constant := 256;
type Opcodes_Lengths_Array is
array (SOR.uint32 range 1 .. MAX_OPCODE_LENGTHS) of SOR.uint8;
type Line_Info_Prologue is record
Unit_Length : SOR.uint32;
Version : SOR.uint16;
Prologue_Length : SOR.uint32;
Min_Isn_Length : SOR.uint8;
Default_Is_Stmt : SOR.uint8;
Line_Base : SOR.int8;
Line_Range : SOR.uint8;
Opcode_Base : SOR.uint8;
Opcode_Lengths : Opcodes_Lengths_Array;
Includes_Offset : SOR.Offset;
File_Names_Offset : SOR.Offset;
end record;
type Search_Entry is record
First : SOR.uint32;
Size : SOR.uint32;
-- Function bounds as offset to the base address.
Sym : SOR.uint32;
-- Symbol offset to get the name.
Line : SOR.uint32;
-- Dwarf line offset.
end record;
type Search_Array is array (Natural range <>) of Search_Entry;
type Search_Array_Access is access Search_Array;
type Dwarf_Context (In_Exception : Boolean := False) is record
Load_Slide : System.Storage_Elements.Integer_Address := 0;
Low, High : Address;
-- Bounds of the module, per the module object file
Obj : SOR.Object_File_Access;
-- The object file containing dwarf sections
Has_Debug : Boolean;
-- True if all debug sections are available
Cache : Search_Array_Access;
-- Quick access to symbol and debug info (when present).
Lines : SOR.Mapped_Stream;
Aranges : SOR.Mapped_Stream;
Info : SOR.Mapped_Stream;
Abbrev : SOR.Mapped_Stream;
-- Dwarf line, aranges, info and abbrev sections
Prologue : Line_Info_Prologue;
Registers : Line_Info_Registers;
Next_Prologue : SOR.Offset;
-- State for lines
end record;
end System.Dwarf_Lines;
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