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
|
// Copyright 2010 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 runtime
import "unsafe"
// The Error interface identifies a run time error.
type Error interface {
error
// RuntimeError is a no-op function but
// serves to distinguish types that are run time
// errors from ordinary errors: a type is a
// run time error if it has a RuntimeError method.
RuntimeError()
}
// A TypeAssertionError explains a failed type assertion.
type TypeAssertionError struct {
interfaceString string
concreteString string
assertedString string
missingMethod string // one method needed by Interface, missing from Concrete
}
func (*TypeAssertionError) RuntimeError() {}
func (e *TypeAssertionError) Error() string {
inter := e.interfaceString
if inter == "" {
inter = "interface"
}
if e.concreteString == "" {
return "interface conversion: " + inter + " is nil, not " + e.assertedString
}
if e.missingMethod == "" {
return "interface conversion: " + inter + " is " + e.concreteString +
", not " + e.assertedString
}
return "interface conversion: " + e.concreteString + " is not " + e.assertedString +
": missing method " + e.missingMethod
}
// For calling from C.
func NewTypeAssertionError(ps1, ps2, ps3 *string, pmeth *string, ret *interface{}) {
var s1, s2, s3, meth string
if ps1 != nil {
s1 = *ps1
}
if ps2 != nil {
s2 = *ps2
}
if ps3 != nil {
s3 = *ps3
}
if pmeth != nil {
meth = *pmeth
}
// For gccgo, strip out quoted strings.
s1 = unquote(s1)
s2 = unquote(s2)
s3 = unquote(s3)
*ret = &TypeAssertionError{s1, s2, s3, meth}
}
// Remove quoted strings from gccgo reflection strings.
func unquote(s string) string {
ls := len(s)
var i int
for i = 0; i < ls; i++ {
if s[i] == '\t' {
break
}
}
if i == ls {
return s
}
var q bool
r := make([]byte, len(s))
j := 0
for i = 0; i < ls; i++ {
if s[i] == '\t' {
q = !q
} else if !q {
r[j] = s[i]
j++
}
}
return string(r[:j])
}
// An errorString represents a runtime error described by a single string.
type errorString string
func (e errorString) RuntimeError() {}
func (e errorString) Error() string {
return "runtime error: " + string(e)
}
// An errorCString represents a runtime error described by a single C string.
// Not "type errorCString uintptr" because of http://golang.org/issue/7084.
type errorCString struct{ cstr uintptr }
func (e errorCString) RuntimeError() {}
func (e errorCString) Error() string {
return "runtime error: " + gostringnocopy((*byte)(unsafe.Pointer(e.cstr)))
}
// For calling from C.
func NewErrorCString(s uintptr, ret *interface{}) {
*ret = errorCString{s}
}
// plainError represents a runtime error described a string without
// the prefix "runtime error: " after invoking errorString.Error().
// See Issue #14965.
type plainError string
func (e plainError) RuntimeError() {}
func (e plainError) Error() string {
return string(e)
}
type stringer interface {
String() string
}
func typestring(interface{}) string
// For calling from C.
// Prints an argument passed to panic.
// There's room for arbitrary complexity here, but we keep it
// simple and handle just a few important cases: int, string, and Stringer.
func Printany(i interface{}) {
switch v := i.(type) {
case nil:
print("nil")
case stringer:
print(v.String())
case error:
print(v.Error())
case int:
print(v)
case string:
print(v)
default:
print("(", typestring(i), ") ", i)
}
}
// called from generated code
func panicwrap(pkg, typ, meth string) {
panic(plainError("value method " + pkg + "." + typ + "." + meth + " called using nil *" + typ + " pointer"))
}
|
