plugeth/accounts/abi/bind/bind.go
2023-02-03 12:29:07 +02:00

482 lines
15 KiB
Go

// 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"
"go/format"
"regexp"
"strings"
"text/template"
"unicode"
"github.com/ethereum/go-ethereum/accounts/abi"
"github.com/ethereum/go-ethereum/log"
)
// Lang is a target programming language selector to generate bindings for.
type Lang int
const (
LangGo Lang = iota
)
func isKeyWord(arg string) bool {
switch arg {
case "break":
case "case":
case "chan":
case "const":
case "continue":
case "default":
case "defer":
case "else":
case "fallthrough":
case "for":
case "func":
case "go":
case "goto":
case "if":
case "import":
case "interface":
case "iota":
case "map":
case "make":
case "new":
case "package":
case "range":
case "return":
case "select":
case "struct":
case "switch":
case "type":
case "var":
default:
return false
}
return true
}
// 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, fsigs []map[string]string, pkg string, lang Lang, libs map[string]string, aliases map[string]string) (string, error) {
var (
// contracts is the map of each individual contract requested binding
contracts = make(map[string]*tmplContract)
// structs is the map of all redeclared structs shared by passed contracts.
structs = make(map[string]*tmplStruct)
// isLib is the map used to flag each encountered library as such
isLib = make(map[string]struct{})
)
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; events, struct definitions; and sort them alphabetically
var (
calls = make(map[string]*tmplMethod)
transacts = make(map[string]*tmplMethod)
events = make(map[string]*tmplEvent)
fallback *tmplMethod
receive *tmplMethod
// identifiers are used to detect duplicated identifiers of functions
// and events. For all calls, transacts and events, abigen will generate
// corresponding bindings. However we have to ensure there is no
// identifier collisions in the bindings of these categories.
callIdentifiers = make(map[string]bool)
transactIdentifiers = make(map[string]bool)
eventIdentifiers = make(map[string]bool)
)
for _, input := range evmABI.Constructor.Inputs {
if hasStruct(input.Type) {
bindStructType[lang](input.Type, structs)
}
}
for _, original := range evmABI.Methods {
// Normalize the method for capital cases and non-anonymous inputs/outputs
normalized := original
normalizedName := methodNormalizer[lang](alias(aliases, original.Name))
// Ensure there is no duplicated identifier
var identifiers = callIdentifiers
if !original.IsConstant() {
identifiers = transactIdentifiers
}
if identifiers[normalizedName] {
return "", fmt.Errorf("duplicated identifier \"%s\"(normalized \"%s\"), use --alias for renaming", original.Name, normalizedName)
}
identifiers[normalizedName] = true
normalized.Name = normalizedName
normalized.Inputs = make([]abi.Argument, len(original.Inputs))
copy(normalized.Inputs, original.Inputs)
for j, input := range normalized.Inputs {
if input.Name == "" || isKeyWord(input.Name) {
normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
}
if hasStruct(input.Type) {
bindStructType[lang](input.Type, structs)
}
}
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)
}
if hasStruct(output.Type) {
bindStructType[lang](output.Type, structs)
}
}
// Append the methods to the call or transact lists
if original.IsConstant() {
calls[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original.Outputs)}
} else {
transacts[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original.Outputs)}
}
}
for _, original := range evmABI.Events {
// Skip anonymous events as they don't support explicit filtering
if original.Anonymous {
continue
}
// Normalize the event for capital cases and non-anonymous outputs
normalized := original
// Ensure there is no duplicated identifier
normalizedName := methodNormalizer[lang](alias(aliases, original.Name))
if eventIdentifiers[normalizedName] {
return "", fmt.Errorf("duplicated identifier \"%s\"(normalized \"%s\"), use --alias for renaming", original.Name, normalizedName)
}
eventIdentifiers[normalizedName] = true
normalized.Name = normalizedName
used := make(map[string]bool)
normalized.Inputs = make([]abi.Argument, len(original.Inputs))
copy(normalized.Inputs, original.Inputs)
for j, input := range normalized.Inputs {
if input.Name == "" || isKeyWord(input.Name) {
normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
}
// Event is a bit special, we need to define event struct in binding,
// ensure there is no camel-case-style name conflict.
for index := 0; ; index++ {
if !used[capitalise(normalized.Inputs[j].Name)] {
used[capitalise(normalized.Inputs[j].Name)] = true
break
}
normalized.Inputs[j].Name = fmt.Sprintf("%s%d", normalized.Inputs[j].Name, index)
}
if hasStruct(input.Type) {
bindStructType[lang](input.Type, structs)
}
}
// Append the event to the accumulator list
events[original.Name] = &tmplEvent{Original: original, Normalized: normalized}
}
// Add two special fallback functions if they exist
if evmABI.HasFallback() {
fallback = &tmplMethod{Original: evmABI.Fallback}
}
if evmABI.HasReceive() {
receive = &tmplMethod{Original: evmABI.Receive}
}
contracts[types[i]] = &tmplContract{
Type: capitalise(types[i]),
InputABI: strings.ReplaceAll(strippedABI, "\"", "\\\""),
InputBin: strings.TrimPrefix(strings.TrimSpace(bytecodes[i]), "0x"),
Constructor: evmABI.Constructor,
Calls: calls,
Transacts: transacts,
Fallback: fallback,
Receive: receive,
Events: events,
Libraries: make(map[string]string),
}
// Function 4-byte signatures are stored in the same sequence
// as types, if available.
if len(fsigs) > i {
contracts[types[i]].FuncSigs = fsigs[i]
}
// Parse library references.
for pattern, name := range libs {
matched, err := regexp.Match("__\\$"+pattern+"\\$__", []byte(contracts[types[i]].InputBin))
if err != nil {
log.Error("Could not search for pattern", "pattern", pattern, "contract", contracts[types[i]], "err", err)
}
if matched {
contracts[types[i]].Libraries[pattern] = name
// keep track that this type is a library
if _, ok := isLib[name]; !ok {
isLib[name] = struct{}{}
}
}
}
}
// Check if that type has already been identified as a library
for i := 0; i < len(types); i++ {
_, ok := isLib[types[i]]
contracts[types[i]].Library = ok
}
// Generate the contract template data content and render it
data := &tmplData{
Package: pkg,
Contracts: contracts,
Libraries: libs,
Structs: structs,
}
buffer := new(bytes.Buffer)
funcs := map[string]interface{}{
"bindtype": bindType[lang],
"bindtopictype": bindTopicType[lang],
"namedtype": namedType[lang],
"capitalise": capitalise,
"decapitalise": decapitalise,
}
tmpl := template.Must(template.New("").Funcs(funcs).Parse(tmplSource[lang]))
if err := tmpl.Execute(buffer, data); err != nil {
return "", err
}
// For Go bindings pass the code through gofmt to clean it up
if lang == LangGo {
code, err := format.Source(buffer.Bytes())
if err != nil {
return "", fmt.Errorf("%v\n%s", err, buffer)
}
return string(code), nil
}
// For all others just return as is for now
return buffer.String(), nil
}
// bindType is a set of type binders that convert Solidity types to some supported
// programming language types.
var bindType = map[Lang]func(kind abi.Type, structs map[string]*tmplStruct) string{
LangGo: bindTypeGo,
}
// bindBasicTypeGo converts basic solidity types(except array, slice and tuple) to Go ones.
func bindBasicTypeGo(kind abi.Type) string {
switch kind.T {
case abi.AddressTy:
return "common.Address"
case abi.IntTy, abi.UintTy:
parts := regexp.MustCompile(`(u)?int([0-9]*)`).FindStringSubmatch(kind.String())
switch parts[2] {
case "8", "16", "32", "64":
return fmt.Sprintf("%sint%s", parts[1], parts[2])
}
return "*big.Int"
case abi.FixedBytesTy:
return fmt.Sprintf("[%d]byte", kind.Size)
case abi.BytesTy:
return "[]byte"
case abi.FunctionTy:
return "[24]byte"
default:
// string, bool types
return kind.String()
}
}
// bindTypeGo converts solidity types to Go ones. 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. BigDecimal).
func bindTypeGo(kind abi.Type, structs map[string]*tmplStruct) string {
switch kind.T {
case abi.TupleTy:
return structs[kind.TupleRawName+kind.String()].Name
case abi.ArrayTy:
return fmt.Sprintf("[%d]", kind.Size) + bindTypeGo(*kind.Elem, structs)
case abi.SliceTy:
return "[]" + bindTypeGo(*kind.Elem, structs)
default:
return bindBasicTypeGo(kind)
}
}
// bindTopicType is a set of type binders that convert Solidity types to some
// supported programming language topic types.
var bindTopicType = map[Lang]func(kind abi.Type, structs map[string]*tmplStruct) string{
LangGo: bindTopicTypeGo,
}
// bindTopicTypeGo converts a Solidity topic type to a Go one. It is almost the same
// functionality as for simple types, but dynamic types get converted to hashes.
func bindTopicTypeGo(kind abi.Type, structs map[string]*tmplStruct) string {
bound := bindTypeGo(kind, structs)
// todo(rjl493456442) according solidity documentation, indexed event
// parameters that are not value types i.e. arrays and structs are not
// stored directly but instead a keccak256-hash of an encoding is stored.
//
// We only convert stringS and bytes to hash, still need to deal with
// array(both fixed-size and dynamic-size) and struct.
if bound == "string" || bound == "[]byte" {
bound = "common.Hash"
}
return bound
}
// bindStructType is a set of type binders that convert Solidity tuple types to some supported
// programming language struct definition.
var bindStructType = map[Lang]func(kind abi.Type, structs map[string]*tmplStruct) string{
LangGo: bindStructTypeGo,
}
// bindStructTypeGo converts a Solidity tuple type to a Go one and records the mapping
// in the given map.
// Notably, this function will resolve and record nested struct recursively.
func bindStructTypeGo(kind abi.Type, structs map[string]*tmplStruct) string {
switch kind.T {
case abi.TupleTy:
// We compose a raw struct name and a canonical parameter expression
// together here. The reason is before solidity v0.5.11, kind.TupleRawName
// is empty, so we use canonical parameter expression to distinguish
// different struct definition. From the consideration of backward
// compatibility, we concat these two together so that if kind.TupleRawName
// is not empty, it can have unique id.
id := kind.TupleRawName + kind.String()
if s, exist := structs[id]; exist {
return s.Name
}
var (
names = make(map[string]bool)
fields []*tmplField
)
for i, elem := range kind.TupleElems {
name := capitalise(kind.TupleRawNames[i])
name = abi.ResolveNameConflict(name, func(s string) bool { return names[s] })
names[name] = true
fields = append(fields, &tmplField{Type: bindStructTypeGo(*elem, structs), Name: name, SolKind: *elem})
}
name := kind.TupleRawName
if name == "" {
name = fmt.Sprintf("Struct%d", len(structs))
}
name = capitalise(name)
structs[id] = &tmplStruct{
Name: name,
Fields: fields,
}
return name
case abi.ArrayTy:
return fmt.Sprintf("[%d]", kind.Size) + bindStructTypeGo(*kind.Elem, structs)
case abi.SliceTy:
return "[]" + bindStructTypeGo(*kind.Elem, structs)
default:
return bindBasicTypeGo(kind)
}
}
// namedType is a set of functions that transform language specific types to
// named versions that may be used inside method names.
var namedType = map[Lang]func(string, abi.Type) string{
LangGo: func(string, abi.Type) string { panic("this shouldn't be needed") },
}
// alias returns an alias of the given string based on the aliasing rules
// or returns itself if no rule is matched.
func alias(aliases map[string]string, n string) string {
if alias, exist := aliases[n]; exist {
return alias
}
return n
}
// methodNormalizer is a name transformer that modifies Solidity method names to
// conform to target language naming conventions.
var methodNormalizer = map[Lang]func(string) string{
LangGo: abi.ToCamelCase,
}
// capitalise makes a camel-case string which starts with an upper case character.
var capitalise = abi.ToCamelCase
// decapitalise makes a camel-case string which starts with a lower case character.
func decapitalise(input string) string {
if len(input) == 0 {
return input
}
goForm := abi.ToCamelCase(input)
return strings.ToLower(goForm[:1]) + goForm[1:]
}
// structured checks whether a list of ABI data types has enough information to
// operate through a proper Go struct or if flat returns are needed.
func structured(args abi.Arguments) bool {
if len(args) < 2 {
return false
}
exists := make(map[string]bool)
for _, out := range args {
// If the name is anonymous, we can't organize into a struct
if out.Name == "" {
return false
}
// If the field name is empty when normalized or collides (var, Var, _var, _Var),
// we can't organize into a struct
field := capitalise(out.Name)
if field == "" || exists[field] {
return false
}
exists[field] = true
}
return true
}
// hasStruct returns an indicator whether the given type is struct, struct slice
// or struct array.
func hasStruct(t abi.Type) bool {
switch t.T {
case abi.SliceTy:
return hasStruct(*t.Elem)
case abi.ArrayTy:
return hasStruct(*t.Elem)
case abi.TupleTy:
return true
default:
return false
}
}