func binaryOpConst(b *builder, op string, A, B *ref) *ref {
va, _ := types.NumConst(A.Type())
vb, _ := types.NumConst(B.Type())
br := func(b bool) *ref {
if b {
return refTrue
}
return refFalse
}
switch op {
case "==":
return br(va == vb)
case "!=":
return br(va != vb)
case ">":
return br(va > vb)
case "<":
return br(va < vb)
case ">=":
return br(va >= vb)
case "<=":
return br(va <= vb)
}
panic("bug")
}
func opAssign(b *builder, dest, src tast.Expr, op *lex8.Token) tast.Stmt {
destRef := dest.R()
srcRef := src.R()
if !destRef.IsSingle() || !srcRef.IsSingle() {
b.Errorf(op.Pos, "%s %s %s", destRef, op.Lit, srcRef)
return nil
} else if !destRef.Addressable {
b.Errorf(op.Pos, "assign to non-addressable")
return nil
}
opLit := parseAssignOp(op.Lit)
destType := destRef.Type()
srcType := srcRef.Type()
if opLit == ">>" || opLit == "<<" {
if v, ok := types.NumConst(srcType); ok {
src = constCast(b, op.Pos, v, src, types.Uint)
if src == nil {
return nil
}
srcRef = src.R()
srcType = types.Uint
}
if !canShift(b, destType, srcType, op.Pos, opLit) {
return nil
}
return &tast.AssignStmt{dest, op, src}
}
if v, ok := types.NumConst(srcType); ok {
src = constCast(b, op.Pos, v, src, destType)
if src == nil {
return nil
}
srcRef = src.R()
srcType = destType
}
if ok, t := types.SameBasic(destType, srcType); ok {
switch t {
case types.Int, types.Int8, types.Uint, types.Uint8:
return &tast.AssignStmt{dest, op, src}
}
}
b.Errorf(op.Pos, "invalid %s %s %s", destType, opLit, srcType)
return nil
}
// allocPrepare checks if the provided types are all allocable, and insert
// implicit type casts if needed. Only literay expression list needs alloc
// prepare.
func allocPrepare(
b *builder, toks []*lex8.Token, lst *tast.ExprList,
) *tast.ExprList {
ret := tast.NewExprList()
for i, tok := range toks {
e := lst.Exprs[i]
t := e.Type()
if types.IsNil(t) {
b.Errorf(tok.Pos, "cannot infer type from nil for %q", tok.Lit)
return nil
}
if v, ok := types.NumConst(t); ok {
e = constCastInt(b, tok.Pos, v, e)
if e == nil {
return nil
}
}
if !types.IsAllocable(t) {
b.Errorf(tok.Pos, "cannot allocate for %s", t)
return nil
}
ret.Append(e)
}
return ret
}
func unaryOpConst(b *builder, opTok *lex8.Token, B tast.Expr) tast.Expr {
op := opTok.Lit
bref := B.R()
if !bref.IsSingle() {
b.Errorf(opTok.Pos, "invalid operation: %q on %s", op, bref)
return nil
}
v, ok := types.NumConst(bref.T)
if !ok {
// TODO: support type const
b.Errorf(opTok.Pos, "typed const operation not implemented")
return nil
}
switch op {
case "+":
return B // just shortcut this
case "-":
return &tast.Const{tast.NewRef(types.NewNumber(-v))}
}
b.Errorf(opTok.Pos, "invalid operation: %q on %s", op, B)
return nil
}
func buildCast(b *builder, expr *ast.CallExpr, t types.T) tast.Expr {
pos := expr.Lparen.Pos
args := buildExprList(b, expr.Args)
if args == nil {
return nil
}
ref := args.R()
if !ref.IsSingle() {
b.Errorf(pos, "cannot convert %s to %s", ref, t)
return nil
}
srcType := ref.T
if c, ok := srcType.(*types.Const); ok {
if v, ok := types.NumConst(srcType); ok && types.IsInteger(t) {
return constCast(b, pos, v, args, t)
}
srcType = c.Type // using the underlying type
}
if types.IsInteger(t) && types.IsInteger(srcType) {
return tast.NewCast(args, t)
}
if regSizeCastable(t, srcType) {
return tast.NewCast(args, t)
}
b.Errorf(pos, "cannot convert from %s to %s", srcType, t)
return nil
}
func buildConst(b *builder, c *tast.Const) *ref {
if _, ok := types.NumConst(c.T); ok {
// untyped consts are just types.
return newRef(c.T, nil)
}
if t, ok := c.T.(types.Basic); ok {
v := c.ConstValue.(int64)
switch t {
case types.Int, types.Uint:
return newRef(c.T, ir.Num(uint32(v)))
case types.Int8, types.Uint8, types.Bool:
return newRef(c.T, ir.Byt(uint8(v)))
default:
panic("other basic types not supported yet")
}
}
if c.T == types.String {
s := c.ConstValue.(string)
ret := b.newTemp(c.T)
b.b.Arith(ret.IR(), nil, "makeStr", b.p.NewString(s))
return ret
}
panic("other const types not supported")
}
func checkArrayIndex(b *builder, index tast.Expr, pos *lex8.Pos) tast.Expr {
t := index.R().T
if v, ok := types.NumConst(t); ok {
if v < 0 {
b.Errorf(pos, "array index is negative: %d", v)
return nil
}
return constCastInt(b, pos, v, index)
}
if !types.IsInteger(t) {
b.Errorf(pos, "index must be an integer")
return nil
}
return index
}
func assign(b *builder, dest, src tast.Expr, op *lex8.Token) tast.Stmt {
destRef := dest.R()
srcRef := src.R()
ndest := destRef.Len()
nsrc := srcRef.Len()
if ndest != nsrc {
b.Errorf(op.Pos, "cannot assign %s to %s", nsrc, ndest)
return nil
}
for i := 0; i < ndest; i++ {
r := destRef.At(i)
if !r.Addressable {
b.Errorf(op.Pos, "assigning to non-addressable")
return nil
}
destType := r.Type()
srcType := srcRef.At(i).Type()
if !types.CanAssign(destType, srcType) {
b.Errorf(op.Pos, "cannot assign %s to %s", srcType, destType)
return nil
}
}
// insert casting if needed
if srcList, ok := tast.MakeExprList(src); ok {
newList := tast.NewExprList()
for i, e := range srcList.Exprs {
t := e.Type()
if types.IsNil(t) {
e = tast.NewCast(e, destRef.At(i).Type())
} else if v, ok := types.NumConst(t); ok {
e = constCast(b, nil, v, e, destRef.At(i).Type())
if e == nil {
panic("bug")
}
}
newList.Append(e)
}
src = newList
}
return &tast.AssignStmt{dest, op, src}
}
func varDeclPrepare(
b *builder, toks []*lex8.Token, lst *tast.ExprList, t types.T,
) *tast.ExprList {
ret := tast.NewExprList()
for i, tok := range toks {
e := lst.Exprs[i]
etype := e.Type()
if types.IsNil(etype) {
e = tast.NewCast(e, t)
} else if v, ok := types.NumConst(etype); ok {
e = constCast(b, tok.Pos, v, e, t)
if e == nil {
return nil
}
}
ret.Append(e)
}
return ret
}
func buildArrayType(b *builder, expr *ast.ArrayTypeExpr) types.T {
t := buildType(b, expr.Type)
if t == nil {
return nil
}
if expr.Len == nil {
// slice
return &types.Slice{t}
}
// array
n := b.buildConstExpr(expr.Len)
if n == nil {
return nil
}
ntype := n.R().T
c, ok := ntype.(*types.Const)
if !ok {
// might be true, false, or other builtin consts
b.Errorf(ast.ExprPos(expr), "array index is not a constant")
return nil
}
if v, ok := types.NumConst(ntype); ok {
if v < 0 {
b.Errorf(ast.ExprPos(expr),
"array index is negative: %d", c.Value,
)
return nil
} else if !types.InRange(v, types.Int) {
b.Errorf(ast.ExprPos(expr), "index out of range of int32")
return nil
}
return &types.Array{T: t, N: int32(v)}
}
// TODO: support typed const
b.Errorf(ast.ExprPos(expr), "typed const not implemented yet")
return nil
}
func buildConst(b *builder, c *tast.Const) *ref {
if _, ok := types.NumConst(c.T); ok {
// untyped consts are just types.
return newRef(c.T, nil)
}
if t, ok := c.T.(types.Basic); ok {
v := c.ConstValue.(int64)
return newRef(c.T, constNumIr(v, t))
}
if c.T == types.String {
s := c.ConstValue.(string)
ret := b.newTemp(c.T)
b.b.Arith(ret.IR(), nil, "makeStr", b.p.NewString(s))
return ret
}
if t, ok := c.T.(*types.Slice); ok {
if bt, ok := t.T.(types.Basic); ok {
switch bt {
case types.Int, types.Uint, types.Int8, types.Uint8, types.Bool:
bs := c.ConstValue.([]byte)
ret := b.newTemp(t)
ref := b.p.NewHeapDat(bs, bt.Size(), bt.RegSizeAlign())
b.b.Arith(ret.IR(), nil, "makeDat", ref)
return ret
default:
panic("other const slices not supported")
}
} else {
panic("not basic type")
}
}
panic("other const types not supported")
}
func buildCast(b *builder, from *ref, t types.T) *ref {
srcType := from.Type()
ret := b.newTemp(t)
if types.IsNil(srcType) {
size := t.Size()
if size == arch8.RegSize {
return newRef(t, ir.Num(0))
}
if _, ok := t.(*types.Slice); !ok {
panic("bug")
}
ret := b.newTemp(t)
b.b.Zero(ret.IR())
return ret
}
if c, ok := srcType.(*types.Const); ok {
if v, ok := types.NumConst(srcType); ok && types.IsInteger(t) {
return newRef(t, constNumIr(v, t))
}
// TODO: we do not support typed const right?
// so why need this line?
srcType = c.Type // using the underlying type
}
if types.IsInteger(t) && types.IsInteger(srcType) {
b.b.Arith(ret.IR(), nil, "cast", from.IR())
return ret
}
if regSizeCastable(t, srcType) {
b.b.Arith(ret.IR(), nil, "", from.IR())
return ret
}
panic("bug")
}
func buildReturnStmt(b *builder, stmt *ast.ReturnStmt) tast.Stmt {
pos := stmt.Kw.Pos
if stmt.Exprs == nil {
if b.retType == nil || b.retNamed {
return &tast.ReturnStmt{}
}
b.Errorf(pos, "expects return %s", fmt8.Join(b.retType, ","))
return nil
}
if b.retType == nil {
b.Errorf(pos, "function expects no return value")
return nil
}
src := b.buildExpr(stmt.Exprs)
if src == nil {
return nil
}
srcRef := src.R()
nret := len(b.retType)
nsrc := srcRef.Len()
if nret != nsrc {
b.Errorf(pos, "expect (%s), returning (%s)",
fmt8.Join(b.retType, ","), srcRef,
)
return nil
}
for i := 0; i < nret; i++ {
t := b.retType[i]
srcType := srcRef.At(i).Type()
if !types.CanAssign(t, srcType) {
b.Errorf(pos, "expect (%s), returning (%s)",
fmt8.Join(b.retType, ","), srcRef,
)
return nil
}
}
// insert implicit type casts
if srcList, ok := tast.MakeExprList(src); ok {
newList := tast.NewExprList()
for i, e := range srcList.Exprs {
t := e.Type()
if types.IsNil(t) {
e = tast.NewCast(e, b.retType[i])
} else if v, ok := types.NumConst(t); ok {
e = constCast(b, nil, v, e, b.retType[i])
if e == nil {
panic("bug")
}
}
newList.Append(e)
}
src = newList
}
return &tast.ReturnStmt{src}
}
func binaryOpConst(b *builder, opTok *lex8.Token, A, B tast.Expr) tast.Expr {
op := opTok.Lit
aref := A.R()
bref := B.R()
if aref.List != nil || bref.List != nil {
b.Errorf(opTok.Pos, "invalid %s %q %s", aref.T, op, bref.T)
return nil
}
va, oka := types.NumConst(aref.T)
vb, okb := types.NumConst(bref.T)
if !(oka && okb) {
b.Errorf(opTok.Pos, "non-numeric consts ops not implemented")
return nil
}
r := func(v int64) tast.Expr {
return &tast.Const{tast.NewRef(types.NewNumber(v))}
}
switch op {
case "+":
return r(va + vb)
case "-":
return r(va - vb)
case "*":
return r(va * vb)
case "&":
return r(va & vb)
case "|":
return r(va | vb)
case "^":
return r(va ^ vb)
case "%":
if vb == 0 {
b.Errorf(opTok.Pos, "modular by zero")
return nil
}
return r(va % vb)
case "/":
if vb == 0 {
b.Errorf(opTok.Pos, "divide by zero")
return nil
}
return r(va / vb)
case "==", "!=", ">", "<", ">=", "<=":
return &tast.OpExpr{A, opTok, B, tast.NewRef(types.Bool)}
case "<<":
if vb < 0 {
b.Errorf(opTok.Pos, "shift with negative value", vb)
return nil
}
return r(va << uint64(vb))
case ">>":
if vb < 0 {
b.Errorf(opTok.Pos, "shift with negative value", vb)
return nil
}
return r(va >> uint64(vb))
}
b.Errorf(opTok.Pos, "%q on consts", op)
return nil
}
func buildCallExpr(b *builder, expr *ast.CallExpr) tast.Expr {
f := b.buildExpr(expr.Func)
if f == nil {
return nil
}
pos := ast.ExprPos(expr.Func)
fref := f.R()
if !fref.IsSingle() {
b.Errorf(pos, "%s is not callable", fref)
return nil
}
if t, ok := fref.T.(*types.Type); ok {
return buildCast(b, expr, t.T)
}
builtin, ok := fref.T.(*types.BuiltInFunc)
if ok {
switch builtin.Name {
case "len":
return buildCallLen(b, expr, f)
case "make":
return buildCallMake(b, expr, f)
}
b.Errorf(pos, "builtin %s() not implemented", builtin.Name)
return nil
}
funcType, ok := fref.T.(*types.Func)
if !ok {
b.Errorf(pos, "function call on non-callable: %s", fref)
return nil
}
args := buildExprList(b, expr.Args)
if args == nil {
return nil
}
argsRef := args.R()
nargs := argsRef.Len()
if nargs != len(funcType.Args) {
b.Errorf(ast.ExprPos(expr), "argument expects (%s), got (%s)",
fmt8.Join(funcType.Args, ","), args,
)
return nil
}
// type check on each argument
for i := 0; i < nargs; i++ {
argType := argsRef.At(i).Type()
expect := funcType.Args[i].T
if !types.CanAssign(expect, argType) {
pos := ast.ExprPos(expr.Args.Exprs[i])
b.Errorf(pos, "argument %d expects %s, got %s",
i+1, expect, argType,
)
return nil
}
}
// insert casting when it is a literal expression list.
callArgs, ok := tast.MakeExprList(args)
if ok {
castedArgs := tast.NewExprList()
for i := 0; i < nargs; i++ {
argExpr := callArgs.Exprs[i]
argType := argExpr.Type()
expect := funcType.Args[i].T
// insert auto casts for consts
if types.IsNil(argType) {
castedArgs.Append(tast.NewCast(argExpr, expect))
} else if _, ok := types.NumConst(argType); ok {
castedArgs.Append(tast.NewCast(argExpr, expect))
} else {
castedArgs.Append(argExpr)
}
}
args = castedArgs
}
retRef := tast.Void
for _, t := range funcType.RetTypes {
retRef = tast.AppendRef(retRef, tast.NewRef(t))
}
return &tast.CallExpr{f, args, retRef}
}
func buildBinaryOpExpr(b *builder, expr *ast.OpExpr) tast.Expr {
opTok := expr.Op
op := opTok.Lit
opPos := opTok.Pos
A := b.buildExpr(expr.A)
if A == nil {
return nil
}
aref := A.R()
if !aref.IsSingle() {
b.Errorf(opPos, "%q on %s", op, aref)
return nil
}
atyp := aref.T
B := b.buildExpr(expr.B)
if B == nil {
return nil
}
bref := B.R()
if !bref.IsSingle() {
b.Errorf(opPos, "%q on %s", op, bref)
return nil
}
btyp := bref.T
if types.IsConst(atyp) && types.IsConst(btyp) {
return binaryOpConst(b, opTok, A, B)
}
if op == ">>" || op == "<<" {
if v, ok := types.NumConst(btyp); ok {
B = constCast(b, opPos, v, B, types.Uint)
if B == nil {
return nil
}
btyp = types.Uint
}
if v, ok := types.NumConst(atyp); ok {
A = constCast(b, opPos, v, A, types.Int)
if A == nil {
return nil
}
atyp = types.Int
}
if !canShift(b, atyp, btyp, opPos, op) {
return nil
}
r := tast.NewRef(atyp)
return &tast.OpExpr{A, opTok, B, r}
}
if v, ok := types.NumConst(atyp); ok {
A = constCast(b, opPos, v, A, btyp)
if A == nil {
return nil
}
atyp = btyp
} else if c, ok := atyp.(*types.Const); ok {
atyp = c.Type
}
if v, ok := types.NumConst(btyp); ok {
B = constCast(b, opPos, v, B, atyp)
if B == nil {
return nil
}
btyp = atyp
} else if c, ok := btyp.(*types.Const); ok {
btyp = c.Type
}
if ok, t := types.SameBasic(atyp, btyp); ok {
switch t {
case types.Int, types.Int8, types.Uint, types.Uint8:
return binaryOpInt(b, opTok, A, B, t)
case types.Bool:
return binaryOpBool(b, opTok, A, B)
case types.Float32:
b.Errorf(opPos, "floating point operations not implemented")
return nil
}
}
if types.IsNil(atyp) && types.IsNil(btyp) {
return binaryOpNil(b, opTok, A, B)
} else if types.BothPointer(atyp, btyp) {
return binaryOpPtr(b, opTok, A, B)
} else if types.BothFuncPointer(atyp, btyp) {
return binaryOpPtr(b, opTok, A, B)
} else if types.BothSlice(atyp, btyp) {
return binaryOpSlice(b, opTok, A, B)
}
b.Errorf(opPos, "invalid operation of %s %s %s", atyp, op, btyp)
if types.IsInteger(atyp) && types.IsInteger(btyp) {
switch op {
case "+", "-", "*", "&", "|", "^", "%", "/",
"==", "!=", ">", "<", ">=", "<=":
b.Errorf(
opPos,
"operation %s needs the same type on both sides",
op,
)
}
}
return nil
}
func buildCallMake(b *builder, expr *ast.CallExpr, f tast.Expr) tast.Expr {
args := buildExprList(b, expr.Args)
if args == nil {
return nil
}
n := args.R().Len()
if n == 0 {
b.Errorf(expr.Lparen.Pos, "make() takes at least one argument")
return nil
}
argsList, ok := tast.MakeExprList(args)
if !ok {
b.Errorf(expr.Lparen.Pos, "make() only takes a literal list")
return nil
}
arg0 := argsList.Exprs[0]
t, ok := arg0.R().T.(*types.Type)
if !ok {
b.Errorf(expr.Lparen.Pos, "make() takes a type as the 1st argument")
return nil
}
switch st := t.T.(type) {
case *types.Slice:
if n != 3 {
b.Errorf(expr.Lparen.Pos, "make() slice takes 3 arguments")
return nil
}
size := argsList.Exprs[1]
pos := ast.ExprPos(expr.Args.Exprs[1])
size = checkArrayIndex(b, size, pos)
if size == nil {
return nil
}
start := argsList.Exprs[2]
startType := start.R().T
startPos := ast.ExprPos(expr.Args.Exprs[2])
if v, ok := types.NumConst(startType); ok {
start = constCastUint(b, startPos, v, start)
if start == nil {
return nil
}
} else if !types.IsBasic(startType, types.Uint) {
pt := types.PointerOf(startType)
if pt == nil || !types.SameType(pt, st.T) {
b.Errorf(startPos,
"make() takes an uint or a typed pointer as the 3rd arg",
)
return nil
}
}
callArgs := tast.NewExprList()
callArgs.Append(arg0)
callArgs.Append(size)
callArgs.Append(start)
r := tast.NewRef(st)
return &tast.CallExpr{f, callArgs, r}
}
b.Errorf(expr.Lparen.Pos, "cannot make() type %s", t.T)
return nil
}
func buildArrayLit(b *builder, lit *ast.ArrayLiteral) tast.Expr {
hold := b.lhsSwap(false)
defer b.lhsRestore(hold)
if lit.Type.Len != nil {
b.Errorf(
ast.ExprPos(lit),
"array literal with length not supported yet",
)
return nil
}
buf := new(bytes.Buffer)
t := buildType(b, lit.Type.Type)
if t == nil {
return nil
}
if !types.IsInteger(t) {
pos := ast.ExprPos(lit.Type.Type)
b.Errorf(pos, "array literal must be integer type")
return nil
}
bt := t.(types.Basic)
if lit.Exprs != nil {
for _, expr := range lit.Exprs.Exprs {
n := b.buildConstExpr(expr)
if n == nil {
return nil
}
ntype := n.R().T
if _, ok := ntype.(*types.Const); !ok {
b.Errorf(ast.ExprPos(expr), "array literal not a constant")
return nil
}
if v, ok := types.NumConst(ntype); ok {
if !types.InRange(v, t) {
b.Errorf(
ast.ExprPos(expr),
"constant out of range of %s",
t,
)
return nil
}
switch bt {
case types.Int, types.Uint:
var bs [4]byte
binary.LittleEndian.PutUint32(bs[:], uint32(v))
buf.Write(bs[:])
case types.Int8, types.Uint8:
buf.Write([]byte{byte(v)})
default:
panic("not integer")
}
}
}
}
ref := tast.NewConstRef(&types.Slice{bt}, buf.Bytes())
return &tast.Const{ref}
}