forked from TrueCloudLab/neoneo-go
3cbd138b67
Previously, struct variables were initialize with VM's nil value which is of primitive type. Thus SETITEM used for struct's field updating wasn't working.
1334 lines
34 KiB
Go
1334 lines
34 KiB
Go
package compiler
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import (
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"encoding/binary"
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"errors"
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"fmt"
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"go/ast"
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"go/constant"
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"go/token"
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"go/types"
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"math"
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"sort"
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"strconv"
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"strings"
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"github.com/nspcc-dev/neo-go/pkg/encoding/address"
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"github.com/nspcc-dev/neo-go/pkg/io"
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"github.com/nspcc-dev/neo-go/pkg/vm"
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"github.com/nspcc-dev/neo-go/pkg/vm/emit"
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"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
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)
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// The identifier of the entry function. Default set to Main.
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const mainIdent = "Main"
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type codegen struct {
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// Information about the program with all its dependencies.
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buildInfo *buildInfo
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// prog holds the output buffer.
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prog *io.BufBinWriter
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// Type information.
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typeInfo *types.Info
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// A mapping of func identifiers with their scope.
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funcs map[string]*funcScope
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// Current funcScope being converted.
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scope *funcScope
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// A mapping from label's names to their ids.
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labels map[labelWithType]uint16
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// A list of nested label names together with evaluation stack depth.
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labelList []labelWithStackSize
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// A label for the for-loop being currently visited.
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currentFor string
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// A label for the switch statement being visited.
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currentSwitch string
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// A label to be used in the next statement.
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nextLabel string
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// Label table for recording jump destinations.
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l []int
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}
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type labelOffsetType byte
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const (
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labelStart labelOffsetType = iota // labelStart is a default label type
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labelEnd // labelEnd is a type for labels that are targets for break
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labelPost // labelPost is a type for labels that are targets for continue
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)
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type labelWithType struct {
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name string
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typ labelOffsetType
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}
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type labelWithStackSize struct {
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name string
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sz int
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}
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// newLabel creates a new label to jump to
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func (c *codegen) newLabel() (l uint16) {
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li := len(c.l)
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if li > math.MaxUint16 {
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c.prog.Err = errors.New("label number is too big")
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return
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}
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l = uint16(li)
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c.l = append(c.l, -1)
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return
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}
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// newNamedLabel creates a new label with a specified name.
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func (c *codegen) newNamedLabel(typ labelOffsetType, name string) (l uint16) {
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l = c.newLabel()
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lt := labelWithType{name: name, typ: typ}
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c.labels[lt] = l
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return
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}
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func (c *codegen) setLabel(l uint16) {
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c.l[l] = c.pc() + 1
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}
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// pc returns the program offset off the last instruction.
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func (c *codegen) pc() int {
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return c.prog.Len() - 1
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}
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func (c *codegen) emitLoadConst(t types.TypeAndValue) {
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if c.prog.Err != nil {
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return
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}
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switch typ := t.Type.Underlying().(type) {
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case *types.Basic:
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c.convertBasicType(t, typ)
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default:
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c.prog.Err = fmt.Errorf("compiler doesn't know how to convert this constant: %v", t)
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return
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}
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}
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func (c *codegen) convertBasicType(t types.TypeAndValue, typ *types.Basic) {
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switch typ.Kind() {
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case types.Int, types.UntypedInt, types.Uint:
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val, _ := constant.Int64Val(t.Value)
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emit.Int(c.prog.BinWriter, val)
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case types.String, types.UntypedString:
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val := constant.StringVal(t.Value)
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emit.String(c.prog.BinWriter, val)
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case types.Bool, types.UntypedBool:
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val := constant.BoolVal(t.Value)
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emit.Bool(c.prog.BinWriter, val)
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case types.Byte:
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val, _ := constant.Int64Val(t.Value)
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b := byte(val)
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emit.Bytes(c.prog.BinWriter, []byte{b})
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default:
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c.prog.Err = fmt.Errorf("compiler doesn't know how to convert this basic type: %v", t)
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return
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}
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}
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func (c *codegen) emitLoadLocal(name string) {
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pos := c.scope.loadLocal(name)
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if pos < 0 {
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c.prog.Err = fmt.Errorf("cannot load local variable with position: %d", pos)
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return
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}
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c.emitLoadLocalPos(pos)
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}
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func (c *codegen) emitLoadLocalPos(pos int) {
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emit.Opcode(c.prog.BinWriter, opcode.DUPFROMALTSTACK)
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emit.Int(c.prog.BinWriter, int64(pos))
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emit.Opcode(c.prog.BinWriter, opcode.PICKITEM)
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}
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func (c *codegen) emitStoreLocal(pos int) {
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emit.Opcode(c.prog.BinWriter, opcode.DUPFROMALTSTACK)
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if pos < 0 {
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c.prog.Err = fmt.Errorf("invalid position to store local: %d", pos)
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return
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}
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emit.Int(c.prog.BinWriter, int64(pos))
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emit.Opcode(c.prog.BinWriter, opcode.ROT)
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emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
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}
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func (c *codegen) emitLoadField(i int) {
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emit.Int(c.prog.BinWriter, int64(i))
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emit.Opcode(c.prog.BinWriter, opcode.PICKITEM)
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}
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func (c *codegen) emitStoreStructField(i int) {
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emit.Int(c.prog.BinWriter, int64(i))
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emit.Opcode(c.prog.BinWriter, opcode.ROT)
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emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
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}
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// convertGlobals traverses the AST and only converts global declarations.
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// If we call this in convertFuncDecl then it will load all global variables
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// into the scope of the function.
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func (c *codegen) convertGlobals(f ast.Node) {
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ast.Inspect(f, func(node ast.Node) bool {
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switch n := node.(type) {
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case *ast.FuncDecl:
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return false
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case *ast.GenDecl:
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// constants are loaded directly so there is no need
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// to store them as a local variables
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if n.Tok != token.CONST {
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ast.Walk(c, n)
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}
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}
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return true
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})
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}
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func (c *codegen) convertFuncDecl(file ast.Node, decl *ast.FuncDecl) {
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var (
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f *funcScope
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ok bool
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)
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f, ok = c.funcs[decl.Name.Name]
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if ok {
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// If this function is a syscall we will not convert it to bytecode.
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if isSyscall(f) {
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return
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}
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c.setLabel(f.label)
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} else {
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f = c.newFunc(decl)
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}
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c.scope = f
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ast.Inspect(decl, c.scope.analyzeVoidCalls) // @OPTIMIZE
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// All globals copied into the scope of the function need to be added
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// to the stack size of the function.
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emit.Int(c.prog.BinWriter, f.stackSize()+countGlobals(file))
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emit.Opcode(c.prog.BinWriter, opcode.NEWARRAY)
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emit.Opcode(c.prog.BinWriter, opcode.TOALTSTACK)
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// We need to handle methods, which in Go, is just syntactic sugar.
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// The method receiver will be passed in as first argument.
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// We check if this declaration has a receiver and load it into scope.
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//
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// FIXME: For now we will hard cast this to a struct. We can later fine tune this
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// to support other types.
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if decl.Recv != nil {
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for _, arg := range decl.Recv.List {
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ident := arg.Names[0]
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// Currently only method receives for struct types is supported.
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_, ok := c.typeInfo.Defs[ident].Type().Underlying().(*types.Struct)
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if !ok {
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c.prog.Err = fmt.Errorf("method receives for non-struct types is not yet supported")
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return
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}
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l := c.scope.newLocal(ident.Name)
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c.emitStoreLocal(l)
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}
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}
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// Load the arguments in scope.
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for _, arg := range decl.Type.Params.List {
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name := arg.Names[0].Name // for now.
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l := c.scope.newLocal(name)
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c.emitStoreLocal(l)
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}
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// Load in all the global variables in to the scope of the function.
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// This is not necessary for syscalls.
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if !isSyscall(f) {
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c.convertGlobals(file)
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}
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ast.Walk(c, decl.Body)
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// If this function returns the void (no return stmt) we will cleanup its junk on the stack.
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if !hasReturnStmt(decl) {
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emit.Opcode(c.prog.BinWriter, opcode.FROMALTSTACK)
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emit.Opcode(c.prog.BinWriter, opcode.DROP)
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emit.Opcode(c.prog.BinWriter, opcode.RET)
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}
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}
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func (c *codegen) Visit(node ast.Node) ast.Visitor {
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if c.prog.Err != nil {
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return nil
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}
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switch n := node.(type) {
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// General declarations.
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// var (
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// x = 2
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// )
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case *ast.GenDecl:
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for _, spec := range n.Specs {
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switch t := spec.(type) {
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case *ast.ValueSpec:
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if len(t.Values) != 0 {
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for i, val := range t.Values {
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ast.Walk(c, val)
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l := c.scope.newLocal(t.Names[i].Name)
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c.emitStoreLocal(l)
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}
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} else if c.isCompoundArrayType(t.Type) {
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emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
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emit.Opcode(c.prog.BinWriter, opcode.NEWARRAY)
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l := c.scope.newLocal(t.Names[0].Name)
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c.emitStoreLocal(l)
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} else if n, ok := c.isStructType(t.Type); ok {
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emit.Int(c.prog.BinWriter, int64(n))
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emit.Opcode(c.prog.BinWriter, opcode.NEWSTRUCT)
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l := c.scope.newLocal(t.Names[0].Name)
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c.emitStoreLocal(l)
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}
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}
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}
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return nil
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case *ast.AssignStmt:
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multiRet := len(n.Rhs) != len(n.Lhs)
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for i := 0; i < len(n.Lhs); i++ {
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switch t := n.Lhs[i].(type) {
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case *ast.Ident:
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switch n.Tok {
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case token.ADD_ASSIGN, token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN, token.REM_ASSIGN:
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c.emitLoadLocal(t.Name)
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ast.Walk(c, n.Rhs[0]) // can only add assign to 1 expr on the RHS
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c.convertToken(n.Tok)
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l := c.scope.loadLocal(t.Name)
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c.emitStoreLocal(l)
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default:
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if i == 0 || !multiRet {
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ast.Walk(c, n.Rhs[i])
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}
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if t.Name == "_" {
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emit.Opcode(c.prog.BinWriter, opcode.DROP)
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} else {
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l := c.scope.loadLocal(t.Name)
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c.emitStoreLocal(l)
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}
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}
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case *ast.SelectorExpr:
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switch expr := t.X.(type) {
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case *ast.Ident:
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ast.Walk(c, n.Rhs[i])
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typ := c.typeInfo.ObjectOf(expr).Type().Underlying()
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if strct, ok := typ.(*types.Struct); ok {
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c.emitLoadLocal(expr.Name) // load the struct
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i := indexOfStruct(strct, t.Sel.Name) // get the index of the field
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c.emitStoreStructField(i) // store the field
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}
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default:
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c.prog.Err = fmt.Errorf("nested selector assigns not supported yet")
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return nil
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}
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// Assignments to index expressions.
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// slice[0] = 10
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case *ast.IndexExpr:
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ast.Walk(c, n.Rhs[i])
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name := t.X.(*ast.Ident).Name
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c.emitLoadLocal(name)
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switch ind := t.Index.(type) {
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case *ast.BasicLit:
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indexStr := ind.Value
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index, err := strconv.Atoi(indexStr)
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if err != nil {
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c.prog.Err = fmt.Errorf("failed to convert slice index to integer")
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return nil
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}
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c.emitStoreStructField(index)
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case *ast.Ident:
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c.emitLoadLocal(ind.Name)
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emit.Opcode(c.prog.BinWriter, opcode.ROT)
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emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
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default:
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c.prog.Err = fmt.Errorf("unsupported index expression")
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return nil
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}
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}
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}
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return nil
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case *ast.SliceExpr:
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name := n.X.(*ast.Ident).Name
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c.emitLoadLocal(name)
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if n.Low != nil {
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ast.Walk(c, n.Low)
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} else {
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emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
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}
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if n.High != nil {
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ast.Walk(c, n.High)
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} else {
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emit.Opcode(c.prog.BinWriter, opcode.OVER)
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emit.Opcode(c.prog.BinWriter, opcode.ARRAYSIZE)
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}
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emit.Opcode(c.prog.BinWriter, opcode.OVER)
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emit.Opcode(c.prog.BinWriter, opcode.SUB)
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emit.Opcode(c.prog.BinWriter, opcode.SUBSTR)
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return nil
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case *ast.ReturnStmt:
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l := c.newLabel()
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c.setLabel(l)
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cnt := 0
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for i := range c.labelList {
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cnt += c.labelList[i].sz
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}
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c.dropItems(cnt)
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// first result should be on top of the stack
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for i := len(n.Results) - 1; i >= 0; i-- {
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ast.Walk(c, n.Results[i])
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}
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emit.Opcode(c.prog.BinWriter, opcode.FROMALTSTACK)
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emit.Opcode(c.prog.BinWriter, opcode.DROP) // Cleanup the stack.
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emit.Opcode(c.prog.BinWriter, opcode.RET)
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return nil
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case *ast.IfStmt:
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lIf := c.newLabel()
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lElse := c.newLabel()
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lElseEnd := c.newLabel()
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|
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if n.Cond != nil {
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ast.Walk(c, n.Cond)
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emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOT, lElse)
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}
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c.setLabel(lIf)
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ast.Walk(c, n.Body)
|
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if n.Else != nil {
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emit.Jmp(c.prog.BinWriter, opcode.JMP, lElseEnd)
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}
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c.setLabel(lElse)
|
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if n.Else != nil {
|
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ast.Walk(c, n.Else)
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}
|
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c.setLabel(lElseEnd)
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return nil
|
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|
|
case *ast.SwitchStmt:
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ast.Walk(c, n.Tag)
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eqOpcode := c.getEqualityOpcode(n.Tag)
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switchEnd, label := c.generateLabel(labelEnd)
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lastSwitch := c.currentSwitch
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c.currentSwitch = label
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c.pushStackLabel(label, 1)
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startLabels := make([]uint16, len(n.Body.List))
|
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for i := range startLabels {
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startLabels[i] = c.newLabel()
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}
|
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for i := range n.Body.List {
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lEnd := c.newLabel()
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lStart := startLabels[i]
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cc := n.Body.List[i].(*ast.CaseClause)
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|
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if l := len(cc.List); l != 0 { // if not `default`
|
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for j := range cc.List {
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emit.Opcode(c.prog.BinWriter, opcode.DUP)
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ast.Walk(c, cc.List[j])
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emit.Opcode(c.prog.BinWriter, eqOpcode)
|
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if j == l-1 {
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emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOT, lEnd)
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} else {
|
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emit.Jmp(c.prog.BinWriter, opcode.JMPIF, lStart)
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}
|
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}
|
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}
|
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|
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c.setLabel(lStart)
|
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last := len(cc.Body) - 1
|
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for j, stmt := range cc.Body {
|
|
if j == last && isFallthroughStmt(stmt) {
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emit.Jmp(c.prog.BinWriter, opcode.JMP, startLabels[i+1])
|
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break
|
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}
|
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ast.Walk(c, stmt)
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}
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, switchEnd)
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c.setLabel(lEnd)
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|
}
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|
|
c.setLabel(switchEnd)
|
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c.dropStackLabel()
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c.currentSwitch = lastSwitch
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|
|
return nil
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|
|
case *ast.BasicLit:
|
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c.emitLoadConst(c.typeInfo.Types[n])
|
|
return nil
|
|
|
|
case *ast.Ident:
|
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if isIdentBool(n) {
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value, err := makeBoolFromIdent(n, c.typeInfo)
|
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if err != nil {
|
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c.prog.Err = err
|
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return nil
|
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}
|
|
c.emitLoadConst(value)
|
|
} else if tv := c.typeInfo.Types[n]; tv.Value != nil {
|
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c.emitLoadConst(tv)
|
|
} else {
|
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c.emitLoadLocal(n.Name)
|
|
}
|
|
return nil
|
|
|
|
case *ast.CompositeLit:
|
|
var typ types.Type
|
|
|
|
switch t := n.Type.(type) {
|
|
case *ast.Ident:
|
|
typ = c.typeInfo.ObjectOf(t).Type().Underlying()
|
|
case *ast.SelectorExpr:
|
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typ = c.typeInfo.ObjectOf(t.Sel).Type().Underlying()
|
|
case *ast.MapType:
|
|
typ = c.typeInfo.TypeOf(t)
|
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default:
|
|
ln := len(n.Elts)
|
|
// ByteArrays needs a different approach than normal arrays.
|
|
if isByteArray(n, c.typeInfo) {
|
|
c.convertByteArray(n)
|
|
return nil
|
|
}
|
|
for i := ln - 1; i >= 0; i-- {
|
|
ast.Walk(c, n.Elts[i])
|
|
}
|
|
emit.Int(c.prog.BinWriter, int64(ln))
|
|
emit.Opcode(c.prog.BinWriter, opcode.PACK)
|
|
return nil
|
|
}
|
|
|
|
switch typ.(type) {
|
|
case *types.Struct:
|
|
c.convertStruct(n)
|
|
case *types.Map:
|
|
c.convertMap(n)
|
|
}
|
|
|
|
return nil
|
|
|
|
case *ast.BinaryExpr:
|
|
switch n.Op {
|
|
case token.LAND:
|
|
next := c.newLabel()
|
|
end := c.newLabel()
|
|
ast.Walk(c, n.X)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMPIF, next)
|
|
emit.Opcode(c.prog.BinWriter, opcode.PUSHF)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, end)
|
|
c.setLabel(next)
|
|
ast.Walk(c, n.Y)
|
|
c.setLabel(end)
|
|
return nil
|
|
|
|
case token.LOR:
|
|
next := c.newLabel()
|
|
end := c.newLabel()
|
|
ast.Walk(c, n.X)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOT, next)
|
|
emit.Opcode(c.prog.BinWriter, opcode.PUSHT)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, end)
|
|
c.setLabel(next)
|
|
ast.Walk(c, n.Y)
|
|
c.setLabel(end)
|
|
return nil
|
|
|
|
default:
|
|
// The AST package will try to resolve all basic literals for us.
|
|
// If the typeinfo.Value is not nil we know that the expr is resolved
|
|
// and needs no further action. e.g. x := 2 + 2 + 2 will be resolved to 6.
|
|
// NOTE: Constants will also be automatically resolved be the AST parser.
|
|
// example:
|
|
// const x = 10
|
|
// x + 2 will results into 12
|
|
tinfo := c.typeInfo.Types[n]
|
|
if tinfo.Value != nil {
|
|
c.emitLoadConst(tinfo)
|
|
return nil
|
|
}
|
|
|
|
ast.Walk(c, n.X)
|
|
ast.Walk(c, n.Y)
|
|
|
|
switch {
|
|
case n.Op == token.ADD:
|
|
// VM has separate opcodes for number and string concatenation
|
|
if isStringType(tinfo.Type) {
|
|
emit.Opcode(c.prog.BinWriter, opcode.CAT)
|
|
} else {
|
|
emit.Opcode(c.prog.BinWriter, opcode.ADD)
|
|
}
|
|
case n.Op == token.EQL:
|
|
// VM has separate opcodes for number and string equality
|
|
op := c.getEqualityOpcode(n.X)
|
|
emit.Opcode(c.prog.BinWriter, op)
|
|
case n.Op == token.NEQ:
|
|
// VM has separate opcodes for number and string equality
|
|
if isStringType(c.typeInfo.Types[n.X].Type) {
|
|
emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
|
|
emit.Opcode(c.prog.BinWriter, opcode.NOT)
|
|
} else {
|
|
emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
|
|
}
|
|
default:
|
|
c.convertToken(n.Op)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
case *ast.CallExpr:
|
|
var (
|
|
f *funcScope
|
|
ok bool
|
|
numArgs = len(n.Args)
|
|
isBuiltin = isBuiltin(n.Fun)
|
|
)
|
|
|
|
switch fun := n.Fun.(type) {
|
|
case *ast.Ident:
|
|
f, ok = c.funcs[fun.Name]
|
|
if !ok && !isBuiltin {
|
|
c.prog.Err = fmt.Errorf("could not resolve function %s", fun.Name)
|
|
return nil
|
|
}
|
|
case *ast.SelectorExpr:
|
|
// If this is a method call we need to walk the AST to load the struct locally.
|
|
// Otherwise this is a function call from a imported package and we can call it
|
|
// directly.
|
|
if c.typeInfo.Selections[fun] != nil {
|
|
ast.Walk(c, fun.X)
|
|
// Dont forget to add 1 extra argument when its a method.
|
|
numArgs++
|
|
}
|
|
|
|
f, ok = c.funcs[fun.Sel.Name]
|
|
// @FIXME this could cause runtime errors.
|
|
f.selector = fun.X.(*ast.Ident)
|
|
if !ok {
|
|
c.prog.Err = fmt.Errorf("could not resolve function %s", fun.Sel.Name)
|
|
return nil
|
|
}
|
|
case *ast.ArrayType:
|
|
// For now we will assume that there are only byte slice conversions.
|
|
// E.g. []byte("foobar") or []byte(scriptHash).
|
|
ast.Walk(c, n.Args[0])
|
|
return nil
|
|
}
|
|
|
|
args := transformArgs(n.Fun, n.Args)
|
|
|
|
// Handle the arguments
|
|
for _, arg := range args {
|
|
ast.Walk(c, arg)
|
|
}
|
|
// Do not swap for builtin functions.
|
|
if !isBuiltin {
|
|
c.emitReverse(numArgs)
|
|
}
|
|
|
|
// Check builtin first to avoid nil pointer on funcScope!
|
|
switch {
|
|
case isBuiltin:
|
|
// Use the ident to check, builtins are not in func scopes.
|
|
// We can be sure builtins are of type *ast.Ident.
|
|
c.convertBuiltin(n)
|
|
case isSyscall(f):
|
|
c.convertSyscall(f.selector.Name, f.name)
|
|
default:
|
|
emit.Call(c.prog.BinWriter, opcode.CALL, f.label)
|
|
}
|
|
|
|
return nil
|
|
|
|
case *ast.SelectorExpr:
|
|
switch t := n.X.(type) {
|
|
case *ast.Ident:
|
|
typ := c.typeInfo.ObjectOf(t).Type().Underlying()
|
|
if strct, ok := typ.(*types.Struct); ok {
|
|
c.emitLoadLocal(t.Name) // load the struct
|
|
i := indexOfStruct(strct, n.Sel.Name)
|
|
c.emitLoadField(i) // load the field
|
|
}
|
|
default:
|
|
c.prog.Err = fmt.Errorf("nested selectors not supported yet")
|
|
return nil
|
|
}
|
|
return nil
|
|
|
|
case *ast.UnaryExpr:
|
|
ast.Walk(c, n.X)
|
|
// From https://golang.org/ref/spec#Operators
|
|
// there can be only following unary operators
|
|
// "+" | "-" | "!" | "^" | "*" | "&" | "<-" .
|
|
// of which last three are not used in SC
|
|
switch n.Op {
|
|
case token.ADD:
|
|
// +10 == 10, no need to do anything in this case
|
|
case token.SUB:
|
|
emit.Opcode(c.prog.BinWriter, opcode.NEGATE)
|
|
case token.NOT:
|
|
emit.Opcode(c.prog.BinWriter, opcode.NOT)
|
|
case token.XOR:
|
|
emit.Opcode(c.prog.BinWriter, opcode.INVERT)
|
|
default:
|
|
c.prog.Err = fmt.Errorf("invalid unary operator: %s", n.Op)
|
|
return nil
|
|
}
|
|
return nil
|
|
|
|
case *ast.IncDecStmt:
|
|
ast.Walk(c, n.X)
|
|
c.convertToken(n.Tok)
|
|
|
|
// For now only identifiers are supported for (post) for stmts.
|
|
// for i := 0; i < 10; i++ {}
|
|
// Where the post stmt is ( i++ )
|
|
if ident, ok := n.X.(*ast.Ident); ok {
|
|
pos := c.scope.loadLocal(ident.Name)
|
|
c.emitStoreLocal(pos)
|
|
}
|
|
return nil
|
|
|
|
case *ast.IndexExpr:
|
|
// Walk the expression, this could be either an Ident or SelectorExpr.
|
|
// This will load local whatever X is.
|
|
ast.Walk(c, n.X)
|
|
|
|
switch n.Index.(type) {
|
|
case *ast.BasicLit:
|
|
t := c.typeInfo.Types[n.Index]
|
|
switch typ := t.Type.Underlying().(type) {
|
|
case *types.Basic:
|
|
c.convertBasicType(t, typ)
|
|
default:
|
|
c.prog.Err = fmt.Errorf("compiler can't use following type as an index: %T", typ)
|
|
return nil
|
|
}
|
|
default:
|
|
ast.Walk(c, n.Index)
|
|
}
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.PICKITEM) // just pickitem here
|
|
|
|
return nil
|
|
|
|
case *ast.BranchStmt:
|
|
var label string
|
|
if n.Label != nil {
|
|
label = n.Label.Name
|
|
} else if n.Tok == token.BREAK {
|
|
label = c.currentSwitch
|
|
} else if n.Tok == token.CONTINUE {
|
|
label = c.currentFor
|
|
}
|
|
|
|
cnt := 0
|
|
for i := len(c.labelList) - 1; i >= 0 && c.labelList[i].name != label; i-- {
|
|
cnt += c.labelList[i].sz
|
|
}
|
|
c.dropItems(cnt)
|
|
|
|
switch n.Tok {
|
|
case token.BREAK:
|
|
end := c.getLabelOffset(labelEnd, label)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, end)
|
|
case token.CONTINUE:
|
|
post := c.getLabelOffset(labelPost, label)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, post)
|
|
}
|
|
|
|
return nil
|
|
|
|
case *ast.LabeledStmt:
|
|
c.nextLabel = n.Label.Name
|
|
|
|
ast.Walk(c, n.Stmt)
|
|
|
|
return nil
|
|
|
|
case *ast.ForStmt:
|
|
fstart, label := c.generateLabel(labelStart)
|
|
fend := c.newNamedLabel(labelEnd, label)
|
|
fpost := c.newNamedLabel(labelPost, label)
|
|
|
|
lastLabel := c.currentFor
|
|
lastSwitch := c.currentSwitch
|
|
c.currentFor = label
|
|
c.currentSwitch = label
|
|
|
|
// Walk the initializer and condition.
|
|
if n.Init != nil {
|
|
ast.Walk(c, n.Init)
|
|
}
|
|
|
|
// Set label and walk the condition.
|
|
c.pushStackLabel(label, 0)
|
|
c.setLabel(fstart)
|
|
if n.Cond != nil {
|
|
ast.Walk(c, n.Cond)
|
|
|
|
// Jump if the condition is false
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOT, fend)
|
|
}
|
|
|
|
// Walk body followed by the iterator (post stmt).
|
|
ast.Walk(c, n.Body)
|
|
c.setLabel(fpost)
|
|
if n.Post != nil {
|
|
ast.Walk(c, n.Post)
|
|
}
|
|
|
|
// Jump back to condition.
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, fstart)
|
|
c.setLabel(fend)
|
|
c.dropStackLabel()
|
|
|
|
c.currentFor = lastLabel
|
|
c.currentSwitch = lastSwitch
|
|
|
|
return nil
|
|
|
|
case *ast.RangeStmt:
|
|
// currently only simple for-range loops are supported
|
|
// for i := range ...
|
|
if n.Value != nil {
|
|
c.prog.Err = errors.New("range loops with value variable are not supported")
|
|
return nil
|
|
}
|
|
|
|
start, label := c.generateLabel(labelStart)
|
|
end := c.newNamedLabel(labelEnd, label)
|
|
post := c.newNamedLabel(labelPost, label)
|
|
|
|
lastFor := c.currentFor
|
|
lastSwitch := c.currentSwitch
|
|
c.currentFor = label
|
|
c.currentSwitch = label
|
|
|
|
ast.Walk(c, n.X)
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.ARRAYSIZE)
|
|
emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
|
|
|
|
c.pushStackLabel(label, 2)
|
|
c.setLabel(start)
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.OVER)
|
|
emit.Opcode(c.prog.BinWriter, opcode.OVER)
|
|
emit.Opcode(c.prog.BinWriter, opcode.LTE) // finish if len <= i
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMPIF, end)
|
|
|
|
if n.Key != nil {
|
|
emit.Opcode(c.prog.BinWriter, opcode.DUP)
|
|
|
|
pos := c.scope.loadLocal(n.Key.(*ast.Ident).Name)
|
|
c.emitStoreLocal(pos)
|
|
}
|
|
|
|
ast.Walk(c, n.Body)
|
|
|
|
c.setLabel(post)
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.INC)
|
|
emit.Jmp(c.prog.BinWriter, opcode.JMP, start)
|
|
|
|
c.setLabel(end)
|
|
c.dropStackLabel()
|
|
|
|
c.currentFor = lastFor
|
|
c.currentSwitch = lastSwitch
|
|
|
|
return nil
|
|
|
|
// We dont really care about assertions for the core logic.
|
|
// The only thing we need is to please the compiler type checking.
|
|
// For this to work properly, we only need to walk the expression
|
|
// not the assertion type.
|
|
case *ast.TypeAssertExpr:
|
|
ast.Walk(c, n.X)
|
|
return nil
|
|
}
|
|
return c
|
|
}
|
|
|
|
func isFallthroughStmt(c ast.Node) bool {
|
|
s, ok := c.(*ast.BranchStmt)
|
|
return ok && s.Tok == token.FALLTHROUGH
|
|
}
|
|
|
|
func (c *codegen) pushStackLabel(name string, size int) {
|
|
c.labelList = append(c.labelList, labelWithStackSize{
|
|
name: name,
|
|
sz: size,
|
|
})
|
|
}
|
|
|
|
func (c *codegen) dropStackLabel() {
|
|
last := len(c.labelList) - 1
|
|
c.dropItems(c.labelList[last].sz)
|
|
c.labelList = c.labelList[:last]
|
|
}
|
|
|
|
func (c *codegen) dropItems(n int) {
|
|
if n < 4 {
|
|
for i := 0; i < n; i++ {
|
|
emit.Opcode(c.prog.BinWriter, opcode.DROP)
|
|
}
|
|
return
|
|
}
|
|
|
|
emit.Int(c.prog.BinWriter, int64(n))
|
|
emit.Opcode(c.prog.BinWriter, opcode.PACK)
|
|
emit.Opcode(c.prog.BinWriter, opcode.DROP)
|
|
}
|
|
|
|
// emitReverse reverses top num items of the stack.
|
|
func (c *codegen) emitReverse(num int) {
|
|
switch num {
|
|
case 2:
|
|
emit.Opcode(c.prog.BinWriter, opcode.SWAP)
|
|
case 3:
|
|
emit.Int(c.prog.BinWriter, 2)
|
|
emit.Opcode(c.prog.BinWriter, opcode.XSWAP)
|
|
default:
|
|
for i := 1; i < num; i++ {
|
|
emit.Int(c.prog.BinWriter, int64(i))
|
|
emit.Opcode(c.prog.BinWriter, opcode.ROLL)
|
|
}
|
|
}
|
|
}
|
|
|
|
// generateLabel returns a new label.
|
|
func (c *codegen) generateLabel(typ labelOffsetType) (uint16, string) {
|
|
name := c.nextLabel
|
|
if name == "" {
|
|
name = fmt.Sprintf("@%d", len(c.l))
|
|
}
|
|
|
|
c.nextLabel = ""
|
|
return c.newNamedLabel(typ, name), name
|
|
}
|
|
|
|
func (c *codegen) getLabelOffset(typ labelOffsetType, name string) uint16 {
|
|
return c.labels[labelWithType{name: name, typ: typ}]
|
|
}
|
|
|
|
func (c *codegen) getEqualityOpcode(expr ast.Expr) opcode.Opcode {
|
|
t, ok := c.typeInfo.Types[expr].Type.Underlying().(*types.Basic)
|
|
if ok && t.Info()&types.IsNumeric != 0 {
|
|
return opcode.NUMEQUAL
|
|
}
|
|
|
|
return opcode.EQUAL
|
|
}
|
|
|
|
// getByteArray returns byte array value from constant expr.
|
|
// Only literals are supported.
|
|
func (c *codegen) getByteArray(expr ast.Expr) []byte {
|
|
switch t := expr.(type) {
|
|
case *ast.CompositeLit:
|
|
if !isByteArray(t, c.typeInfo) {
|
|
return nil
|
|
}
|
|
buf := make([]byte, len(t.Elts))
|
|
for i := 0; i < len(t.Elts); i++ {
|
|
t := c.typeInfo.Types[t.Elts[i]]
|
|
val, _ := constant.Int64Val(t.Value)
|
|
buf[i] = byte(val)
|
|
}
|
|
return buf
|
|
case *ast.CallExpr:
|
|
if tv := c.typeInfo.Types[t.Args[0]]; tv.Value != nil {
|
|
val := constant.StringVal(tv.Value)
|
|
return []byte(val)
|
|
}
|
|
|
|
return nil
|
|
default:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
func (c *codegen) convertSyscall(api, name string) {
|
|
api, ok := syscalls[api][name]
|
|
if !ok {
|
|
c.prog.Err = fmt.Errorf("unknown VM syscall api: %s", name)
|
|
return
|
|
}
|
|
emit.Syscall(c.prog.BinWriter, api)
|
|
|
|
// This NOP instruction is basically not needed, but if we do, we have a
|
|
// one to one matching avm file with neo-python which is very nice for debugging.
|
|
emit.Opcode(c.prog.BinWriter, opcode.NOP)
|
|
}
|
|
|
|
func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
|
|
var name string
|
|
switch t := expr.Fun.(type) {
|
|
case *ast.Ident:
|
|
name = t.Name
|
|
case *ast.SelectorExpr:
|
|
name = t.Sel.Name
|
|
}
|
|
|
|
switch name {
|
|
case "len":
|
|
arg := expr.Args[0]
|
|
typ := c.typeInfo.Types[arg].Type
|
|
if isStringType(typ) {
|
|
emit.Opcode(c.prog.BinWriter, opcode.SIZE)
|
|
} else {
|
|
emit.Opcode(c.prog.BinWriter, opcode.ARRAYSIZE)
|
|
}
|
|
case "append":
|
|
arg := expr.Args[0]
|
|
typ := c.typeInfo.Types[arg].Type
|
|
if isByteArrayType(typ) {
|
|
emit.Opcode(c.prog.BinWriter, opcode.CAT)
|
|
} else {
|
|
emit.Opcode(c.prog.BinWriter, opcode.OVER)
|
|
emit.Opcode(c.prog.BinWriter, opcode.SWAP)
|
|
emit.Opcode(c.prog.BinWriter, opcode.APPEND)
|
|
}
|
|
case "panic":
|
|
arg := expr.Args[0]
|
|
if isExprNil(arg) {
|
|
emit.Opcode(c.prog.BinWriter, opcode.DROP)
|
|
emit.Opcode(c.prog.BinWriter, opcode.THROW)
|
|
} else if isStringType(c.typeInfo.Types[arg].Type) {
|
|
ast.Walk(c, arg)
|
|
emit.Syscall(c.prog.BinWriter, "Neo.Runtime.Log")
|
|
emit.Opcode(c.prog.BinWriter, opcode.THROW)
|
|
} else {
|
|
c.prog.Err = errors.New("panic should have string or nil argument")
|
|
}
|
|
case "SHA256":
|
|
emit.Opcode(c.prog.BinWriter, opcode.SHA256)
|
|
case "SHA1":
|
|
emit.Opcode(c.prog.BinWriter, opcode.SHA1)
|
|
case "Hash256":
|
|
emit.Opcode(c.prog.BinWriter, opcode.HASH256)
|
|
case "Hash160":
|
|
emit.Opcode(c.prog.BinWriter, opcode.HASH160)
|
|
case "VerifySignature":
|
|
emit.Opcode(c.prog.BinWriter, opcode.VERIFY)
|
|
case "AppCall":
|
|
numArgs := len(expr.Args) - 1
|
|
c.emitReverse(numArgs)
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.APPCALL)
|
|
buf := c.getByteArray(expr.Args[0])
|
|
if len(buf) != 20 {
|
|
c.prog.Err = errors.New("invalid script hash")
|
|
}
|
|
|
|
c.prog.WriteBytes(buf)
|
|
case "Equals":
|
|
emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
|
|
case "FromAddress":
|
|
// We can be sure that this is a ast.BasicLit just containing a simple
|
|
// address string. Note that the string returned from calling Value will
|
|
// contain double quotes that need to be stripped.
|
|
addressStr := expr.Args[0].(*ast.BasicLit).Value
|
|
addressStr = strings.Replace(addressStr, "\"", "", 2)
|
|
uint160, err := address.StringToUint160(addressStr)
|
|
if err != nil {
|
|
c.prog.Err = err
|
|
return
|
|
}
|
|
bytes := uint160.BytesBE()
|
|
emit.Bytes(c.prog.BinWriter, bytes)
|
|
}
|
|
}
|
|
|
|
// transformArgs returns a list of function arguments
|
|
// which should be put on stack.
|
|
// There are special cases for builtins:
|
|
// 1. When using AppCall, script hash is a part of the instruction so
|
|
// it should be emitted after APPCALL.
|
|
// 2. With FromAddress, parameter conversion is happening at compile-time
|
|
// so there is no need to push parameters on stack and perform an actual call
|
|
// 3. With panic, generated code depends on if argument was nil or a string so
|
|
// it should be handled accordingly.
|
|
func transformArgs(fun ast.Expr, args []ast.Expr) []ast.Expr {
|
|
switch f := fun.(type) {
|
|
case *ast.SelectorExpr:
|
|
if f.Sel.Name == "AppCall" || f.Sel.Name == "FromAddress" {
|
|
return args[1:]
|
|
}
|
|
case *ast.Ident:
|
|
if f.Name == "panic" {
|
|
return args[1:]
|
|
}
|
|
}
|
|
|
|
return args
|
|
}
|
|
|
|
func (c *codegen) convertByteArray(lit *ast.CompositeLit) {
|
|
buf := make([]byte, len(lit.Elts))
|
|
for i := 0; i < len(lit.Elts); i++ {
|
|
t := c.typeInfo.Types[lit.Elts[i]]
|
|
val, _ := constant.Int64Val(t.Value)
|
|
buf[i] = byte(val)
|
|
}
|
|
emit.Bytes(c.prog.BinWriter, buf)
|
|
}
|
|
|
|
func (c *codegen) convertMap(lit *ast.CompositeLit) {
|
|
emit.Opcode(c.prog.BinWriter, opcode.NEWMAP)
|
|
for i := range lit.Elts {
|
|
elem := lit.Elts[i].(*ast.KeyValueExpr)
|
|
emit.Opcode(c.prog.BinWriter, opcode.DUP)
|
|
ast.Walk(c, elem.Key)
|
|
ast.Walk(c, elem.Value)
|
|
emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
|
|
}
|
|
}
|
|
|
|
func (c *codegen) convertStruct(lit *ast.CompositeLit) {
|
|
// Create a new structScope to initialize and store
|
|
// the positions of its variables.
|
|
strct, ok := c.typeInfo.TypeOf(lit).Underlying().(*types.Struct)
|
|
if !ok {
|
|
c.prog.Err = fmt.Errorf("the given literal is not of type struct: %v", lit)
|
|
return
|
|
}
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.NOP)
|
|
emit.Int(c.prog.BinWriter, int64(strct.NumFields()))
|
|
emit.Opcode(c.prog.BinWriter, opcode.NEWSTRUCT)
|
|
|
|
// We need to locally store all the fields, even if they are not initialized.
|
|
// We will initialize all fields to their "zero" value.
|
|
for i := 0; i < strct.NumFields(); i++ {
|
|
sField := strct.Field(i)
|
|
fieldAdded := false
|
|
|
|
// Fields initialized by the program.
|
|
for _, field := range lit.Elts {
|
|
f := field.(*ast.KeyValueExpr)
|
|
fieldName := f.Key.(*ast.Ident).Name
|
|
|
|
if sField.Name() == fieldName {
|
|
emit.Opcode(c.prog.BinWriter, opcode.DUP)
|
|
|
|
pos := indexOfStruct(strct, fieldName)
|
|
emit.Int(c.prog.BinWriter, int64(pos))
|
|
|
|
ast.Walk(c, f.Value)
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
|
|
fieldAdded = true
|
|
break
|
|
}
|
|
}
|
|
if fieldAdded {
|
|
continue
|
|
}
|
|
|
|
typeAndVal, err := typeAndValueForField(sField)
|
|
if err != nil {
|
|
c.prog.Err = err
|
|
return
|
|
}
|
|
|
|
emit.Opcode(c.prog.BinWriter, opcode.DUP)
|
|
emit.Int(c.prog.BinWriter, int64(i))
|
|
c.emitLoadConst(typeAndVal)
|
|
emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
|
|
}
|
|
}
|
|
|
|
func (c *codegen) convertToken(tok token.Token) {
|
|
switch tok {
|
|
case token.ADD_ASSIGN:
|
|
emit.Opcode(c.prog.BinWriter, opcode.ADD)
|
|
case token.SUB_ASSIGN:
|
|
emit.Opcode(c.prog.BinWriter, opcode.SUB)
|
|
case token.MUL_ASSIGN:
|
|
emit.Opcode(c.prog.BinWriter, opcode.MUL)
|
|
case token.QUO_ASSIGN:
|
|
emit.Opcode(c.prog.BinWriter, opcode.DIV)
|
|
case token.REM_ASSIGN:
|
|
emit.Opcode(c.prog.BinWriter, opcode.MOD)
|
|
case token.ADD:
|
|
emit.Opcode(c.prog.BinWriter, opcode.ADD)
|
|
case token.SUB:
|
|
emit.Opcode(c.prog.BinWriter, opcode.SUB)
|
|
case token.MUL:
|
|
emit.Opcode(c.prog.BinWriter, opcode.MUL)
|
|
case token.QUO:
|
|
emit.Opcode(c.prog.BinWriter, opcode.DIV)
|
|
case token.REM:
|
|
emit.Opcode(c.prog.BinWriter, opcode.MOD)
|
|
case token.LSS:
|
|
emit.Opcode(c.prog.BinWriter, opcode.LT)
|
|
case token.LEQ:
|
|
emit.Opcode(c.prog.BinWriter, opcode.LTE)
|
|
case token.GTR:
|
|
emit.Opcode(c.prog.BinWriter, opcode.GT)
|
|
case token.GEQ:
|
|
emit.Opcode(c.prog.BinWriter, opcode.GTE)
|
|
case token.EQL:
|
|
emit.Opcode(c.prog.BinWriter, opcode.NUMEQUAL)
|
|
case token.NEQ:
|
|
emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
|
|
case token.DEC:
|
|
emit.Opcode(c.prog.BinWriter, opcode.DEC)
|
|
case token.INC:
|
|
emit.Opcode(c.prog.BinWriter, opcode.INC)
|
|
case token.NOT:
|
|
emit.Opcode(c.prog.BinWriter, opcode.NOT)
|
|
case token.AND:
|
|
emit.Opcode(c.prog.BinWriter, opcode.AND)
|
|
case token.OR:
|
|
emit.Opcode(c.prog.BinWriter, opcode.OR)
|
|
case token.SHL:
|
|
emit.Opcode(c.prog.BinWriter, opcode.SHL)
|
|
case token.SHR:
|
|
emit.Opcode(c.prog.BinWriter, opcode.SHR)
|
|
case token.XOR:
|
|
emit.Opcode(c.prog.BinWriter, opcode.XOR)
|
|
default:
|
|
c.prog.Err = fmt.Errorf("compiler could not convert token: %s", tok)
|
|
return
|
|
}
|
|
}
|
|
|
|
func (c *codegen) newFunc(decl *ast.FuncDecl) *funcScope {
|
|
f := newFuncScope(decl, c.newLabel())
|
|
c.funcs[f.name] = f
|
|
return f
|
|
}
|
|
|
|
// CodeGen compiles the program to bytecode.
|
|
func CodeGen(info *buildInfo) ([]byte, error) {
|
|
pkg := info.program.Package(info.initialPackage)
|
|
c := &codegen{
|
|
buildInfo: info,
|
|
prog: io.NewBufBinWriter(),
|
|
l: []int{},
|
|
funcs: map[string]*funcScope{},
|
|
labels: map[labelWithType]uint16{},
|
|
typeInfo: &pkg.Info,
|
|
}
|
|
|
|
// Resolve the entrypoint of the program.
|
|
main, mainFile := resolveEntryPoint(mainIdent, pkg)
|
|
if main == nil {
|
|
c.prog.Err = fmt.Errorf("could not find func main. Did you forget to declare it? ")
|
|
return []byte{}, c.prog.Err
|
|
}
|
|
|
|
funUsage := analyzeFuncUsage(info.program.AllPackages)
|
|
|
|
// Bring all imported functions into scope.
|
|
for _, pkg := range info.program.AllPackages {
|
|
for _, f := range pkg.Files {
|
|
c.resolveFuncDecls(f)
|
|
}
|
|
}
|
|
|
|
// convert the entry point first.
|
|
c.convertFuncDecl(mainFile, main)
|
|
|
|
// sort map keys to generate code deterministically.
|
|
keys := make([]*types.Package, 0, len(info.program.AllPackages))
|
|
for p := range info.program.AllPackages {
|
|
keys = append(keys, p)
|
|
}
|
|
sort.Slice(keys, func(i, j int) bool { return keys[i].Path() < keys[j].Path() })
|
|
|
|
// Generate the code for the program.
|
|
for _, k := range keys {
|
|
pkg := info.program.AllPackages[k]
|
|
c.typeInfo = &pkg.Info
|
|
|
|
for _, f := range pkg.Files {
|
|
for _, decl := range f.Decls {
|
|
switch n := decl.(type) {
|
|
case *ast.FuncDecl:
|
|
// Don't convert the function if it's not used. This will save a lot
|
|
// of bytecode space.
|
|
if n.Name.Name != mainIdent && funUsage.funcUsed(n.Name.Name) {
|
|
c.convertFuncDecl(f, n)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if c.prog.Err != nil {
|
|
return nil, c.prog.Err
|
|
}
|
|
buf := c.prog.Bytes()
|
|
if err := c.writeJumps(buf); err != nil {
|
|
return nil, err
|
|
}
|
|
return buf, nil
|
|
}
|
|
|
|
func (c *codegen) resolveFuncDecls(f *ast.File) {
|
|
for _, decl := range f.Decls {
|
|
switch n := decl.(type) {
|
|
case *ast.FuncDecl:
|
|
if n.Name.Name != mainIdent {
|
|
c.newFunc(n)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *codegen) writeJumps(b []byte) error {
|
|
ctx := vm.NewContext(b)
|
|
for op, _, err := ctx.Next(); err == nil && ctx.NextIP() < len(b); op, _, err = ctx.Next() {
|
|
switch op {
|
|
case opcode.JMP, opcode.JMPIFNOT, opcode.JMPIF, opcode.CALL:
|
|
// we can't use arg returned by ctx.Next() because it is copied
|
|
nextIP := ctx.NextIP()
|
|
arg := b[nextIP-2:]
|
|
|
|
index := binary.LittleEndian.Uint16(arg)
|
|
if int(index) > len(c.l) {
|
|
return fmt.Errorf("unexpected label number: %d (max %d)", index, len(c.l))
|
|
}
|
|
offset := c.l[index] - nextIP + 3
|
|
if offset > math.MaxUint16 {
|
|
return fmt.Errorf("label offset is too big at the instruction %d: %d (max %d)",
|
|
nextIP-3, offset, math.MaxUint16)
|
|
}
|
|
binary.LittleEndian.PutUint16(arg, uint16(offset))
|
|
}
|
|
}
|
|
return nil
|
|
}
|