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go-ethereum-modded-tocallarg/accounts/abi/abigen/bindv2.go
jwasinger 64bd21393e
cmd/abigen, accounts/abi/bind: implement abigen version 2 (#31379)
This PR implements a new version of the abigen utility (v2) which exists
along with the pre-existing v1 version.

Abigen is a utility command provided by go-ethereum that, given a
solidity contract ABI definition, will generate Go code to transact/call
the contract methods, converting the method parameters/results and
structures defined in the contract into corresponding Go types. This is
useful for preventing the need to write custom boilerplate code for
contract interactions.

Methods in the generated bindings perform encoding between Go types and
Solidity ABI-encoded packed bytecode, as well as some action (e.g.
`eth_call` or creating and submitting a transaction). This limits the
flexibility of how the generated bindings can be used, and prevents
easily adding new functionality, as it will make the generated bindings
larger for each feature added.

Abigen v2 was conceived of by the observation that the only
functionality that generated Go bindings ought to perform is conversion
between Go types and ABI-encoded packed data. Go-ethereum already
provides various APIs which in conjunction with conversion methods
generated in v2 bindings can cover all functionality currently provided
by v1, and facilitate all other previously-desired use-cases.

## Generating Bindings

To generate contract bindings using abigen v2, invoke the `abigen`
command with the `--v2` flag. The functionality of all other flags is
preserved between the v2 and v1 versions.

## What is Generated in the Bindings

The execution of `abigen --v2` generates Go code containing methods
which convert between Go types and corresponding ABI-encoded data
expected by the contract. For each input-accepting contract method and
the constructor, a "packing" method is generated in the binding which
converts from Go types to the corresponding packed solidity expected by
the contract. If a method returns output, an "unpacking" method is
generated to convert this output from ABI-encoded data to the
corresponding Go types.

For contracts which emit events, an unpacking method is defined for each
event to unpack the corresponding raw log to the Go type that it
represents.

Likewise, where custom errors are defined by contracts, an unpack method
is generated to unpack raw error data into a Go type.

## Using the Generated Bindings

For a smooth user-experience, abigen v2 comes with a number of utility
functions to be used in conjunction with the generated bindings for
performing common contract interaction use-cases. These include:

* filtering for historical logs of a given topic
* watching the chain for emission of logs with a given topic
* contract deployment methods
* Call/Transact methods

https://geth.ethereum.org will be updated to include a new tutorial page
for abigen v2 with full code examples. The page currently exists in a
PR: https://github.com/ethereum/go-ethereum/pull/31390 .

There are also extensive examples of interactions with contract bindings
in [test
cases](cc855c7ede/accounts/abi/bind/v2/lib_test.go)
provided with this PR.

---------

Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
2025-03-17 15:56:55 +01:00

373 lines
12 KiB
Go

// Copyright 2024 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 abigen
import (
"bytes"
"fmt"
"go/format"
"reflect"
"regexp"
"slices"
"sort"
"strings"
"text/template"
"unicode"
"github.com/ethereum/go-ethereum/accounts/abi"
)
// underlyingBindType returns a string representation of the Go type
// that corresponds to the given ABI type, panicking if it is not a
// pointer.
func underlyingBindType(typ abi.Type) string {
goType := typ.GetType()
if goType.Kind() != reflect.Pointer {
panic("trying to retrieve underlying bind type of non-pointer type.")
}
return goType.Elem().String()
}
// isPointerType returns true if the underlying type is a pointer.
func isPointerType(typ abi.Type) bool {
return typ.GetType().Kind() == reflect.Pointer
}
// OLD:
// binder is used during the conversion of an ABI definition into Go bindings
// (as part of the execution of BindV2). In contrast to contractBinder, binder
// contains binding-generation-state that is shared between contracts:
//
// a global struct map of structs emitted by all contracts is tracked and expanded.
// Structs generated in the bindings are not prefixed with the contract name
// that uses them (to keep the generated bindings less verbose).
//
// This contrasts to other per-contract state (constructor/method/event/error,
// pack/unpack methods) which are guaranteed to be unique because of their
// association with the uniquely-named owning contract (whether prefixed in the
// generated symbol name, or as a member method on a contract struct).
//
// In addition, binder contains the input alias map. In BindV2, a binder is
// instantiated to produce a set of tmplContractV2 and tmplStruct objects from
// the provided ABI definition. These are used as part of the input to rendering
// the binding template.
// NEW:
// binder is used to translate an ABI definition into a set of data-structures
// that will be used to render the template and produce Go bindings. This can
// be thought of as the "backend" that sanitizes the ABI definition to a format
// that can be directly rendered with minimal complexity in the template.
//
// The input data to the template rendering consists of:
// - the set of all contracts requested for binding, each containing
// methods/events/errors to emit pack/unpack methods for.
// - the set of structures defined by the contracts, and created
// as part of the binding process.
type binder struct {
// contracts is the map of each individual contract requested binding.
// It is keyed by the contract name provided in the ABI definition.
contracts map[string]*tmplContractV2
// structs is the map of all emitted structs from contracts being bound.
// it is keyed by a unique identifier generated from the name of the owning contract
// and the solidity type signature of the struct
structs map[string]*tmplStruct
// aliases is a map for renaming instances of named events/functions/errors
// to specified values. it is keyed by source symbol name, and values are
// what the replacement name should be.
aliases map[string]string
}
// BindStructType registers the type to be emitted as a struct in the
// bindings.
func (b *binder) BindStructType(typ abi.Type) {
bindStructType(typ, b.structs)
}
// contractBinder holds state for binding of a single contract. It is a type
// registry for compiling maps of identifiers that will be emitted in generated
// bindings.
type contractBinder struct {
binder *binder
// all maps are keyed by the original (non-normalized) name of the symbol in question
// from the provided ABI definition.
calls map[string]*tmplMethod
events map[string]*tmplEvent
errors map[string]*tmplError
callIdentifiers map[string]bool
eventIdentifiers map[string]bool
errorIdentifiers map[string]bool
}
func newContractBinder(binder *binder) *contractBinder {
return &contractBinder{
binder,
make(map[string]*tmplMethod),
make(map[string]*tmplEvent),
make(map[string]*tmplError),
make(map[string]bool),
make(map[string]bool),
make(map[string]bool),
}
}
// registerIdentifier applies alias renaming, name normalization (conversion
// from snake to camel-case), and registers the normalized name in the specified identifier map.
// It returns an error if the normalized name already exists in the map.
func (cb *contractBinder) registerIdentifier(identifiers map[string]bool, original string) (normalized string, err error) {
normalized = abi.ToCamelCase(alias(cb.binder.aliases, original))
// Name shouldn't start with a digit. It will make the generated code invalid.
if len(normalized) > 0 && unicode.IsDigit(rune(normalized[0])) {
normalized = fmt.Sprintf("E%s", normalized)
normalized = abi.ResolveNameConflict(normalized, func(name string) bool {
_, ok := identifiers[name]
return ok
})
}
if _, ok := identifiers[normalized]; ok {
return "", fmt.Errorf("duplicate symbol '%s'", normalized)
}
identifiers[normalized] = true
return normalized, nil
}
// bindMethod registers a method to be emitted in the bindings. The name, inputs
// and outputs are normalized. If any inputs are struct-type their structs are
// registered to be emitted in the bindings. Any methods that return more than
// one output have their results gathered into a struct.
func (cb *contractBinder) bindMethod(original abi.Method) error {
normalized := original
normalizedName, err := cb.registerIdentifier(cb.callIdentifiers, original.Name)
if err != nil {
return err
}
normalized.Name = normalizedName
normalized.Inputs = normalizeArgs(original.Inputs)
for _, input := range normalized.Inputs {
if hasStruct(input.Type) {
cb.binder.BindStructType(input.Type)
}
}
normalized.Outputs = normalizeArgs(original.Outputs)
for _, output := range normalized.Outputs {
if hasStruct(output.Type) {
cb.binder.BindStructType(output.Type)
}
}
var isStructured bool
// If the call returns multiple values, gather them into a struct
if len(normalized.Outputs) > 1 {
isStructured = true
}
cb.calls[original.Name] = &tmplMethod{
Original: original,
Normalized: normalized,
Structured: isStructured,
}
return nil
}
// normalize a set of arguments by stripping underscores, giving a generic name
// in the case where the arg name collides with a reserved Go keyword, and finally
// converting to camel-case.
func normalizeArgs(args abi.Arguments) abi.Arguments {
args = slices.Clone(args)
used := make(map[string]bool)
for i, input := range args {
if isKeyWord(input.Name) {
args[i].Name = fmt.Sprintf("arg%d", i)
}
args[i].Name = abi.ToCamelCase(args[i].Name)
if args[i].Name == "" {
args[i].Name = fmt.Sprintf("arg%d", i)
} else {
args[i].Name = strings.ToLower(args[i].Name[:1]) + args[i].Name[1:]
}
for index := 0; ; index++ {
if !used[args[i].Name] {
used[args[i].Name] = true
break
}
args[i].Name = fmt.Sprintf("%s%d", args[i].Name, index)
}
}
return args
}
// normalizeErrorOrEventFields normalizes errors/events for emitting through
// bindings: Any anonymous fields are given generated names.
func (cb *contractBinder) normalizeErrorOrEventFields(originalInputs abi.Arguments) abi.Arguments {
normalizedArguments := normalizeArgs(originalInputs)
for _, input := range normalizedArguments {
if hasStruct(input.Type) {
cb.binder.BindStructType(input.Type)
}
}
return normalizedArguments
}
// bindEvent normalizes an event and registers it to be emitted in the bindings.
func (cb *contractBinder) bindEvent(original abi.Event) error {
// Skip anonymous events as they don't support explicit filtering
if original.Anonymous {
return nil
}
normalizedName, err := cb.registerIdentifier(cb.eventIdentifiers, original.Name)
if err != nil {
return err
}
normalized := original
normalized.Name = normalizedName
normalized.Inputs = cb.normalizeErrorOrEventFields(original.Inputs)
cb.events[original.Name] = &tmplEvent{Original: original, Normalized: normalized}
return nil
}
// bindError normalizes an error and registers it to be emitted in the bindings.
func (cb *contractBinder) bindError(original abi.Error) error {
normalizedName, err := cb.registerIdentifier(cb.errorIdentifiers, original.Name)
if err != nil {
return err
}
normalized := original
normalized.Name = normalizedName
normalized.Inputs = cb.normalizeErrorOrEventFields(original.Inputs)
cb.errors[original.Name] = &tmplError{Original: original, Normalized: normalized}
return nil
}
// parseLibraryDeps extracts references to library dependencies from the unlinked
// hex string deployment bytecode.
func parseLibraryDeps(unlinkedCode string) (res []string) {
reMatchSpecificPattern, err := regexp.Compile(`__\$([a-f0-9]+)\$__`)
if err != nil {
panic(err)
}
for _, match := range reMatchSpecificPattern.FindAllStringSubmatch(unlinkedCode, -1) {
res = append(res, match[1])
}
return res
}
// iterSorted iterates the map in the lexicographic order of the keys calling
// onItem on each. If the callback returns an error, iteration is halted and
// the error is returned from iterSorted.
func iterSorted[V any](inp map[string]V, onItem func(string, V) error) error {
var sortedKeys []string
for key := range inp {
sortedKeys = append(sortedKeys, key)
}
sort.Strings(sortedKeys)
for _, key := range sortedKeys {
if err := onItem(key, inp[key]); err != nil {
return err
}
}
return nil
}
// BindV2 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 as opposed to having to
// manually maintain hard coded strings that break on runtime.
func BindV2(types []string, abis []string, bytecodes []string, pkg string, libs map[string]string, aliases map[string]string) (string, error) {
b := binder{
contracts: make(map[string]*tmplContractV2),
structs: make(map[string]*tmplStruct),
aliases: aliases,
}
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
}
for _, input := range evmABI.Constructor.Inputs {
if hasStruct(input.Type) {
bindStructType(input.Type, b.structs)
}
}
cb := newContractBinder(&b)
err = iterSorted(evmABI.Methods, func(_ string, original abi.Method) error {
return cb.bindMethod(original)
})
if err != nil {
return "", err
}
err = iterSorted(evmABI.Events, func(_ string, original abi.Event) error {
return cb.bindEvent(original)
})
if err != nil {
return "", err
}
err = iterSorted(evmABI.Errors, func(_ string, original abi.Error) error {
return cb.bindError(original)
})
if err != nil {
return "", err
}
b.contracts[types[i]] = newTmplContractV2(types[i], abis[i], bytecodes[i], evmABI.Constructor, cb)
}
invertedLibs := make(map[string]string)
for pattern, name := range libs {
invertedLibs[name] = pattern
}
data := tmplDataV2{
Package: pkg,
Contracts: b.contracts,
Libraries: invertedLibs,
Structs: b.structs,
}
for typ, contract := range data.Contracts {
for _, depPattern := range parseLibraryDeps(contract.InputBin) {
data.Contracts[typ].Libraries[libs[depPattern]] = depPattern
}
}
buffer := new(bytes.Buffer)
funcs := map[string]interface{}{
"bindtype": bindType,
"bindtopictype": bindTopicType,
"capitalise": abi.ToCamelCase,
"decapitalise": decapitalise,
"ispointertype": isPointerType,
"underlyingbindtype": underlyingBindType,
}
tmpl := template.Must(template.New("").Funcs(funcs).Parse(tmplSourceV2))
if err := tmpl.Execute(buffer, data); err != nil {
return "", err
}
// Pass the code through gofmt to clean it up
code, err := format.Source(buffer.Bytes())
if err != nil {
return "", fmt.Errorf("%v\n%s", err, buffer)
}
return string(code), nil
}