1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
------------------------------------------------------------------------------
-- --
-- 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) 2009-2020, 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_Address (C : Dwarf_Context)
return System.Address;
pragma Inline (Low_Address);
-- Return the lowest address of C, accounting for the module load address
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 : 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
Low, High : System.Storage_Elements.Storage_Offset;
-- Bounds of the module, per the module object file
Obj : SOR.Object_File_Access;
-- The object file containing dwarf sections
Load_Address : System.Address := System.Null_Address;
-- The address at which the object file was loaded at run time
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;
|
