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compiler: append bytes >0x80 properly

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NeoVM encoding for int(0x80) is []byte{0x80, 0x00} and
byte constant can be used both as integer and as an element
of byte-slice. Thus special case needs to be taken in
`append`.
This commit is contained in:
Evgeniy Stratonikov 2021-02-16 16:20:19 +03:00
parent 608df7fb21
commit fc3b840335
2 changed files with 90 additions and 18 deletions
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36
pkg/compiler/codegen.go
View file

@ -783,7 +783,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
ln := len(n.Elts)
// ByteArrays needs a different approach than normal arrays.
if isByteSlice(typ) {
c.convertByteArray(n)
c.convertByteArray(n.Elts)
return nil
}
for i := ln - 1; i >= 0; i-- {
@ -1621,20 +1621,24 @@ func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
case "append":
arg := expr.Args[0]
typ := c.typeInfo.Types[arg].Type
c.emitReverse(len(expr.Args))
ast.Walk(c, arg)
emit.Opcodes(c.prog.BinWriter, opcode.DUP, opcode.ISNULL)
if isByteSlice(typ) {
emit.Instruction(c.prog.BinWriter, opcode.JMPIFNOT, []byte{2 + 3})
if isByteSlice(typ) {
emit.Opcodes(c.prog.BinWriter, opcode.DROP, opcode.PUSH0, opcode.NEWBUFFER)
emit.Opcodes(c.prog.BinWriter, opcode.DROP, opcode.PUSHDATA1, 0)
if expr.Ellipsis.IsValid() {
ast.Walk(c, expr.Args[1])
} else {
emit.Opcodes(c.prog.BinWriter, opcode.DROP, opcode.NEWARRAY0, opcode.NOP)
c.convertByteArray(expr.Args[1:])
}
// Jump target.
for range expr.Args[1:] {
if isByteSlice(typ) {
emit.Opcodes(c.prog.BinWriter, opcode.SWAP, opcode.CAT)
emit.Opcodes(c.prog.BinWriter, opcode.CAT)
} else {
emit.Opcodes(c.prog.BinWriter, opcode.DUP, opcode.ROT, opcode.APPEND)
emit.Instruction(c.prog.BinWriter, opcode.JMPIFNOT, []byte{2 + 2})
emit.Opcodes(c.prog.BinWriter, opcode.DROP, opcode.NEWARRAY0)
for _, e := range expr.Args[1:] {
emit.Opcodes(c.prog.BinWriter, opcode.DUP)
ast.Walk(c, e)
emit.Opcodes(c.prog.BinWriter, opcode.APPEND)
}
}
case "panic":
@ -1696,7 +1700,7 @@ func transformArgs(fun ast.Expr, args []ast.Expr) []ast.Expr {
}
case *ast.Ident:
switch f.Name {
case "make", "copy":
case "make", "copy", "append":
return nil
}
}
@ -1709,11 +1713,11 @@ func (c *codegen) emitConvert(typ stackitem.Type) {
emit.Instruction(c.prog.BinWriter, opcode.CONVERT, []byte{byte(typ)})
}
func (c *codegen) convertByteArray(lit *ast.CompositeLit) {
buf := make([]byte, len(lit.Elts))
func (c *codegen) convertByteArray(elems []ast.Expr) {
buf := make([]byte, len(elems))
varIndices := []int{}
for i := 0; i < len(lit.Elts); i++ {
t := c.typeAndValueOf(lit.Elts[i])
for i := 0; i < len(elems); i++ {
t := c.typeAndValueOf(elems[i])
if t.Value != nil {
val, _ := constant.Int64Val(t.Value)
buf[i] = byte(val)
@ -1726,7 +1730,7 @@ func (c *codegen) convertByteArray(lit *ast.CompositeLit) {
for _, i := range varIndices {
emit.Opcodes(c.prog.BinWriter, opcode.DUP)
emit.Int(c.prog.BinWriter, int64(i))
ast.Walk(c, lit.Elts[i])
ast.Walk(c, elems[i])
emit.Opcodes(c.prog.BinWriter, opcode.SETITEM)
}
}

68
pkg/compiler/slice_test.go
View file

@ -336,6 +336,74 @@ func TestSliceOperations(t *testing.T) {
runTestCases(t, sliceTestCases)
}
func TestByteSlices(t *testing.T) {
testCases := []testCase{
{
"append bytes bigger than 0x79",
`package foo
func Main() []byte {
var z []byte
z = append(z, 0x78, 0x79, 0x80, 0x81, 0xFF)
return z
}`,
[]byte{0x78, 0x79, 0x80, 0x81, 0xFF},
},
{
"append bytes bigger than 0x79, not nil",
`package foo
func Main() []byte {
z := []byte{0x78}
z = append(z, 0x79, 0x80, 0x81, 0xFF)
return z
}`,
[]byte{0x78, 0x79, 0x80, 0x81, 0xFF},
},
{
"append bytes bigger than 0x79, function return",
`package foo
func getByte() byte { return 0x80 }
func Main() []byte {
var z []byte
z = append(z, 0x78, 0x79, getByte(), 0x81, 0xFF)
return z
}`,
[]byte{0x78, 0x79, 0x80, 0x81, 0xFF},
},
{
"append ints bigger than 0x79, function return byte",
`package foo
func getByte() byte { return 0x80 }
func Main() []int {
var z []int
z = append(z, 0x78, int(getByte()))
return z
}`,
[]stackitem.Item{stackitem.Make(0x78), stackitem.Make(0x80)},
},
{
"slice literal, bytes bigger than 0x79, function return",
`package foo
func getByte() byte { return 0x80 }
func Main() []byte {
z := []byte{0x79, getByte(), 0x81}
return z
}`,
[]byte{0x79, 0x80, 0x81},
},
{
"compare bytes as integers",
`package foo
func getByte1() byte { return 0x79 }
func getByte2() byte { return 0x80 }
func Main() bool {
return getByte1() < getByte2()
}`,
true,
},
}
runTestCases(t, testCases)
}
func TestSubsliceCompound(t *testing.T) {
src := `package foo
func Main() []int {