go-ethereum/rlp/rlpgen/types.go

99 lines
2.4 KiB
Go

package main
import (
"fmt"
"go/types"
"reflect"
)
// typeReflectKind gives the reflect.Kind that represents typ.
func typeReflectKind(typ types.Type) reflect.Kind {
switch typ := typ.(type) {
case *types.Basic:
k := typ.Kind()
if k >= types.Bool && k <= types.Complex128 {
// value order matches for Bool..Complex128
return reflect.Bool + reflect.Kind(k-types.Bool)
}
if k == types.String {
return reflect.String
}
if k == types.UnsafePointer {
return reflect.UnsafePointer
}
panic(fmt.Errorf("unhandled BasicKind %v", k))
case *types.Array:
return reflect.Array
case *types.Chan:
return reflect.Chan
case *types.Interface:
return reflect.Interface
case *types.Map:
return reflect.Map
case *types.Pointer:
return reflect.Ptr
case *types.Signature:
return reflect.Func
case *types.Slice:
return reflect.Slice
case *types.Struct:
return reflect.Struct
default:
panic(fmt.Errorf("unhandled type %T", typ))
}
}
// nonZeroCheck returns the expression that checks whether 'v' is a non-zero value of type 'vtyp'.
func nonZeroCheck(v string, vtyp types.Type, qualify types.Qualifier) string {
// Resolve type name.
typ := resolveUnderlying(vtyp)
switch typ := typ.(type) {
case *types.Basic:
k := typ.Kind()
switch {
case k == types.Bool:
return v
case k >= types.Uint && k <= types.Complex128:
return fmt.Sprintf("%s != 0", v)
case k == types.String:
return fmt.Sprintf(`%s != ""`, v)
default:
panic(fmt.Errorf("unhandled BasicKind %v", k))
}
case *types.Array, *types.Struct:
return fmt.Sprintf("%s != (%s{})", v, types.TypeString(vtyp, qualify))
case *types.Interface, *types.Pointer, *types.Signature:
return fmt.Sprintf("%s != nil", v)
case *types.Slice, *types.Map:
return fmt.Sprintf("len(%s) > 0", v)
default:
panic(fmt.Errorf("unhandled type %T", typ))
}
}
// isBigInt checks whether 'typ' is "math/big".Int.
func isBigInt(typ types.Type) bool {
named, ok := typ.(*types.Named)
if !ok {
return false
}
name := named.Obj()
return name.Pkg().Path() == "math/big" && name.Name() == "Int"
}
// isByte checks whether the underlying type of 'typ' is uint8.
func isByte(typ types.Type) bool {
basic, ok := resolveUnderlying(typ).(*types.Basic)
return ok && basic.Kind() == types.Uint8
}
func resolveUnderlying(typ types.Type) types.Type {
for {
t := typ.Underlying()
if t == typ {
return t
}
typ = t
}
}