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
|
/* DWARF 2 abbreviations
Copyright (C) 1994-2021 Free Software Foundation, Inc.
Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
Inc. with support from Florida State University (under contract
with the Ada Joint Program Office), and Silicon Graphics, Inc.
Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
based on Fred Fish's (Cygnus Support) implementation of DWARF 1
support.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "dwarf2/read.h"
#include "dwarf2/abbrev.h"
#include "dwarf2/leb.h"
#include "bfd.h"
/* Hash function for an abbrev. */
static hashval_t
hash_abbrev (const void *item)
{
const struct abbrev_info *info = (const struct abbrev_info *) item;
/* Warning: if you change this next line, you must also update the
other code in this class using the _with_hash functions. */
return info->number;
}
/* Comparison function for abbrevs. */
static int
eq_abbrev (const void *lhs, const void *rhs)
{
const struct abbrev_info *l_info = (const struct abbrev_info *) lhs;
const struct abbrev_info *r_info = (const struct abbrev_info *) rhs;
return l_info->number == r_info->number;
}
/* Abbreviation tables.
In DWARF version 2, the description of the debugging information is
stored in a separate .debug_abbrev section. Before we read any
dies from a section we read in all abbreviations and install them
in a hash table. */
abbrev_table::abbrev_table (sect_offset off)
: sect_off (off),
m_abbrevs (htab_create_alloc (20, hash_abbrev, eq_abbrev,
nullptr, xcalloc, xfree))
{
}
/* Add an abbreviation to the table. */
void
abbrev_table::add_abbrev (struct abbrev_info *abbrev)
{
void **slot = htab_find_slot_with_hash (m_abbrevs.get (), abbrev,
abbrev->number, INSERT);
*slot = abbrev;
}
/* Read in an abbrev table. */
abbrev_table_up
abbrev_table::read (struct dwarf2_section_info *section,
sect_offset sect_off)
{
bfd *abfd = section->get_bfd_owner ();
const gdb_byte *abbrev_ptr;
struct abbrev_info *cur_abbrev;
unsigned int abbrev_number, bytes_read;
abbrev_table_up abbrev_table (new struct abbrev_table (sect_off));
struct obstack *obstack = &abbrev_table->m_abbrev_obstack;
/* Caller must ensure this. */
gdb_assert (section->readin);
abbrev_ptr = section->buffer + to_underlying (sect_off);
abbrev_number = read_unsigned_leb128 (abfd, abbrev_ptr, &bytes_read);
abbrev_ptr += bytes_read;
/* Loop until we reach an abbrev number of 0. */
while (abbrev_number)
{
/* Start without any attrs. */
obstack_blank (obstack, offsetof (abbrev_info, attrs));
cur_abbrev = (struct abbrev_info *) obstack_base (obstack);
/* Read in abbrev header. */
cur_abbrev->number = abbrev_number;
cur_abbrev->tag
= (enum dwarf_tag) read_unsigned_leb128 (abfd, abbrev_ptr,
&bytes_read);
abbrev_ptr += bytes_read;
cur_abbrev->has_children = read_1_byte (abfd, abbrev_ptr);
abbrev_ptr += 1;
/* Now read in declarations. */
int num_attrs = 0;
for (;;)
{
struct attr_abbrev cur_attr;
cur_attr.name
= (enum dwarf_attribute) read_unsigned_leb128 (abfd, abbrev_ptr,
&bytes_read);
abbrev_ptr += bytes_read;
cur_attr.form
= (enum dwarf_form) read_unsigned_leb128 (abfd, abbrev_ptr,
&bytes_read);
abbrev_ptr += bytes_read;
if (cur_attr.form == DW_FORM_implicit_const)
{
cur_attr.implicit_const = read_signed_leb128 (abfd, abbrev_ptr,
&bytes_read);
abbrev_ptr += bytes_read;
}
else
cur_attr.implicit_const = -1;
if (cur_attr.name == 0)
break;
++num_attrs;
obstack_grow (obstack, &cur_attr, sizeof (cur_attr));
}
cur_abbrev = (struct abbrev_info *) obstack_finish (obstack);
cur_abbrev->num_attrs = num_attrs;
abbrev_table->add_abbrev (cur_abbrev);
/* Get next abbreviation.
Under Irix6 the abbreviations for a compilation unit are not
always properly terminated with an abbrev number of 0.
Exit loop if we encounter an abbreviation which we have
already read (which means we are about to read the abbreviations
for the next compile unit) or if the end of the abbreviation
table is reached. */
if ((unsigned int) (abbrev_ptr - section->buffer) >= section->size)
break;
abbrev_number = read_unsigned_leb128 (abfd, abbrev_ptr, &bytes_read);
abbrev_ptr += bytes_read;
if (abbrev_table->lookup_abbrev (abbrev_number) != NULL)
break;
}
return abbrev_table;
}
|
