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
|
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package dwarf
import (
"fmt"
"strconv"
)
// Parse the type units stored in a DWARF4 .debug_types section. Each
// type unit defines a single primary type and an 8-byte signature.
// Other sections may then use formRefSig8 to refer to the type.
// The typeUnit format is a single type with a signature. It holds
// the same data as a compilation unit.
type typeUnit struct {
unit
toff Offset // Offset to signature type within data.
name string // Name of .debug_type section.
cache Type // Cache the type, nil to start.
}
// Parse a .debug_types section.
func (d *Data) parseTypes(name string, types []byte) error {
b := makeBuf(d, unknownFormat{}, name, 0, types)
for len(b.data) > 0 {
base := b.off
n, dwarf64 := b.unitLength()
if n != Offset(uint32(n)) {
b.error("type unit length overflow")
return b.err
}
hdroff := b.off
vers := int(b.uint16())
if vers != 4 {
b.error("unsupported DWARF version " + strconv.Itoa(vers))
return b.err
}
var ao uint64
if !dwarf64 {
ao = uint64(b.uint32())
} else {
ao = b.uint64()
}
atable, err := d.parseAbbrev(ao, vers)
if err != nil {
return err
}
asize := b.uint8()
sig := b.uint64()
var toff uint32
if !dwarf64 {
toff = b.uint32()
} else {
to64 := b.uint64()
if to64 != uint64(uint32(to64)) {
b.error("type unit type offset overflow")
return b.err
}
toff = uint32(to64)
}
boff := b.off
d.typeSigs[sig] = &typeUnit{
unit: unit{
base: base,
off: boff,
data: b.bytes(int(n - (b.off - hdroff))),
atable: atable,
asize: int(asize),
vers: vers,
is64: dwarf64,
},
toff: Offset(toff),
name: name,
}
if b.err != nil {
return b.err
}
}
return nil
}
// Return the type for a type signature.
func (d *Data) sigToType(sig uint64) (Type, error) {
tu := d.typeSigs[sig]
if tu == nil {
return nil, fmt.Errorf("no type unit with signature %v", sig)
}
if tu.cache != nil {
return tu.cache, nil
}
b := makeBuf(d, tu, tu.name, tu.off, tu.data)
r := &typeUnitReader{d: d, tu: tu, b: b}
t, err := d.readType(tu.name, r, tu.toff, make(map[Offset]Type), nil)
if err != nil {
return nil, err
}
tu.cache = t
return t, nil
}
// typeUnitReader is a typeReader for a tagTypeUnit.
type typeUnitReader struct {
d *Data
tu *typeUnit
b buf
err error
}
// Seek to a new position in the type unit.
func (tur *typeUnitReader) Seek(off Offset) {
tur.err = nil
doff := off - tur.tu.off
if doff < 0 || doff >= Offset(len(tur.tu.data)) {
tur.err = fmt.Errorf("%s: offset %d out of range; max %d", tur.tu.name, doff, len(tur.tu.data))
return
}
tur.b = makeBuf(tur.d, tur.tu, tur.tu.name, off, tur.tu.data[doff:])
}
// AddressSize returns the size in bytes of addresses in the current type unit.
func (tur *typeUnitReader) AddressSize() int {
return tur.tu.unit.asize
}
// Next reads the next Entry from the type unit.
func (tur *typeUnitReader) Next() (*Entry, error) {
if tur.err != nil {
return nil, tur.err
}
if len(tur.tu.data) == 0 {
return nil, nil
}
e := tur.b.entry(tur.tu.atable, tur.tu.base)
if tur.b.err != nil {
tur.err = tur.b.err
return nil, tur.err
}
return e, nil
}
// clone returns a new reader for the type unit.
func (tur *typeUnitReader) clone() typeReader {
return &typeUnitReader{
d: tur.d,
tu: tur.tu,
b: makeBuf(tur.d, tur.tu, tur.tu.name, tur.tu.off, tur.tu.data),
}
}
// offset returns the current offset.
func (tur *typeUnitReader) offset() Offset {
return tur.b.off
}
|
