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
|
// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package bind generates Ethereum contract Go bindings.
//
// Detailed usage document and tutorial available on the go-ethereum Wiki page:
// https://github.com/ethereum/go-ethereum/wiki/Native-DApps:-Go-bindings-to-Ethereum-contracts
package bind
import (
"bytes"
"fmt"
"strings"
"text/template"
"unicode"
"github.com/ethereum/go-ethereum/accounts/abi"
"golang.org/x/tools/imports"
)
// Bind generates a Go wrapper around a contract ABI. This wrapper isn't meant
// to be used as is in client code, but rather as an intermediate struct which
// enforces compile time type safety and naming convention opposed to having to
// manually maintain hard coded strings that break on runtime.
func Bind(types []string, abis []string, bytecodes []string, pkg string) (string, error) {
// Process each individual contract requested binding
contracts := make(map[string]*tmplContract)
for i := 0; i < len(types); i++ {
// Parse the actual ABI to generate the binding for
evmABI, err := abi.JSON(strings.NewReader(abis[i]))
if err != nil {
return "", err
}
// Strip any whitespace from the JSON ABI
strippedABI := strings.Map(func(r rune) rune {
if unicode.IsSpace(r) {
return -1
}
return r
}, abis[i])
// Extract the call and transact methods, and sort them alphabetically
var (
calls = make(map[string]*tmplMethod)
transacts = make(map[string]*tmplMethod)
)
for _, original := range evmABI.Methods {
// Normalize the method for capital cases and non-anonymous inputs/outputs
normalized := original
normalized.Name = capitalise(original.Name)
normalized.Inputs = make([]abi.Argument, len(original.Inputs))
copy(normalized.Inputs, original.Inputs)
for j, input := range normalized.Inputs {
if input.Name == "" {
normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
}
}
normalized.Outputs = make([]abi.Argument, len(original.Outputs))
copy(normalized.Outputs, original.Outputs)
for j, output := range normalized.Outputs {
if output.Name != "" {
normalized.Outputs[j].Name = capitalise(output.Name)
}
}
// Append the methos to the call or transact lists
if original.Const {
calls[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original)}
} else {
transacts[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original)}
}
}
contracts[types[i]] = &tmplContract{
Type: capitalise(types[i]),
InputABI: strippedABI,
InputBin: strings.TrimSpace(bytecodes[i]),
Constructor: evmABI.Constructor,
Calls: calls,
Transacts: transacts,
}
}
// Generate the contract template data content and render it
data := &tmplData{
Package: pkg,
Contracts: contracts,
}
buffer := new(bytes.Buffer)
funcs := map[string]interface{}{
"bindtype": bindType,
}
tmpl := template.Must(template.New("").Funcs(funcs).Parse(tmplSource))
if err := tmpl.Execute(buffer, data); err != nil {
return "", err
}
// Pass the code through goimports to clean it up and double check
code, err := imports.Process("", buffer.Bytes(), nil)
if err != nil {
return "", fmt.Errorf("%v\n%s", err, buffer)
}
return string(code), nil
}
// bindType converts a Solidity type to a Go one. Since there is no clear mapping
// from all Solidity types to Go ones (e.g. uint17), those that cannot be exactly
// mapped will use an upscaled type (e.g. *big.Int).
func bindType(kind abi.Type) string {
stringKind := kind.String()
switch {
case stringKind == "address":
return "common.Address"
case stringKind == "address[]":
return "[]common.Address"
case strings.HasPrefix(stringKind, "bytes"):
if stringKind == "bytes" {
return "[]byte"
}
return fmt.Sprintf("[%s]byte", stringKind[5:])
case strings.HasPrefix(stringKind, "int"):
switch stringKind[:3] {
case "8", "16", "32", "64":
return stringKind
}
return "*big.Int"
case strings.HasPrefix(stringKind, "uint"):
switch stringKind[:4] {
case "8", "16", "32", "64":
return stringKind
}
return "*big.Int"
default:
return stringKind
}
}
// capitalise makes the first character of a string upper case.
func capitalise(input string) string {
return strings.ToUpper(input[:1]) + input[1:]
}
// structured checks whether a method has enough information to return a proper
// Go struct ot if flat returns are needed.
func structured(method abi.Method) bool {
if len(method.Outputs) < 2 {
return false
}
for _, out := range method.Outputs {
if out.Name == "" {
return false
}
}
return true
}
|
