go-ethereum/accounts/abi/reflect.go
Jeffrey Wilcke 91a7a4a786 accounts/abi: fixed unpacking in to already slice interfaces
Previously it was assumed that wheneven type `[]interface{}` was given
that the interface was empty. The abigen rightfully assumed that
interface slices which already have pre-allocated variable sets to be
assigned.

This PR fixes that by checking that the given `[]interface{}` is larger
than zero and assigns each value using the generic `set` function (this
function has also been moved to abi/reflect.go) and checks whether the
assignment was possible.

The generic assignment function `set` now also deals with pointers
(useful for interface slice mentioned above) by dereferencing the
pointer until it finds a setable type.
2016-05-11 13:36:27 +02:00

98 lines
2.8 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 abi
import (
"fmt"
"reflect"
)
// indirect recursively dereferences the value until it either gets the value
// or finds a big.Int
func indirect(v reflect.Value) reflect.Value {
if v.Kind() == reflect.Ptr && v.Elem().Type() != big_t {
return indirect(v.Elem())
}
return v
}
// reflectIntKind returns the reflect using the given size and
// unsignedness.
func reflectIntKind(unsigned bool, size int) reflect.Kind {
switch size {
case 8:
if unsigned {
return reflect.Uint8
}
return reflect.Int8
case 16:
if unsigned {
return reflect.Uint16
}
return reflect.Int16
case 32:
if unsigned {
return reflect.Uint32
}
return reflect.Int32
case 64:
if unsigned {
return reflect.Uint64
}
return reflect.Int64
}
return reflect.Ptr
}
// mustArrayToBytesSlice creates a new byte slice with the exact same size as value
// and copies the bytes in value to the new slice.
func mustArrayToByteSlice(value reflect.Value) reflect.Value {
slice := reflect.MakeSlice(reflect.TypeOf([]byte{}), value.Len(), value.Len())
reflect.Copy(slice, value)
return slice
}
// set attempts to assign src to dst by either setting, copying or otherwise.
//
// set is a bit more lenient when it comes to assignment and doesn't force an as
// strict ruleset as bare `reflect` does.
func set(dst, src reflect.Value, output Argument) error {
dstType := dst.Type()
srcType := src.Type()
switch {
case dstType.AssignableTo(src.Type()):
dst.Set(src)
case dstType.Kind() == reflect.Array && srcType.Kind() == reflect.Slice:
if !dstType.Elem().AssignableTo(r_byte) {
return fmt.Errorf("abi: cannot unmarshal %v in to array of elem %v", src.Type(), dstType.Elem())
}
if dst.Len() < output.Type.SliceSize {
return fmt.Errorf("abi: cannot unmarshal src (len=%d) in to dst (len=%d)", output.Type.SliceSize, dst.Len())
}
reflect.Copy(dst, src)
case dstType.Kind() == reflect.Interface:
dst.Set(src)
case dstType.Kind() == reflect.Ptr:
return set(dst.Elem(), src, output)
default:
return fmt.Errorf("abi: cannot unmarshal %v in to %v", src.Type(), dst.Type())
}
return nil
}