func buildIdent(b *builder, ident *lex8.Token) tast.Expr {
s := b.scope.Query(ident.Lit)
if s == nil {
b.Errorf(ident.Pos, "undefined identifier %s", ident.Lit)
return nil
}
b.refSym(s, ident.Pos)
t := s.ObjType.(types.T)
switch s.Type {
case tast.SymVar, tast.SymField:
ref := tast.NewAddressableRef(t)
return &tast.Ident{ident, ref, s}
case tast.SymConst, tast.SymStruct, tast.SymType, tast.SymImport:
ref := tast.NewRef(t)
return &tast.Ident{ident, ref, s}
case tast.SymFunc:
if t, ok := t.(*types.Func); ok {
if t.MethodFunc == nil {
return &tast.Ident{ident, tast.NewRef(t), s}
}
if b.this == nil {
panic("this missing")
}
ref := &tast.Ref{T: t.MethodFunc, Recv: b.this}
return &tast.Ident{ident, ref, s}
}
return &tast.Ident{ident, tast.NewRef(t), s}
default:
b.Errorf(ident.Pos, "todo: token type: %s", tast.SymStr(s.Type))
return nil
}
}
func buildPkgSym(
b *builder, m *ast.MemberExpr, pkg *types.Pkg,
) (*tast.Ref, *sym8.Symbol) {
sym := findPackageSym(b, m.Sub, pkg)
if sym == nil {
return nil, nil
}
if pkg.Lang == "asm8" {
switch sym.Type {
case asm8.SymVar:
return tast.NewRef(types.Uint), sym
case asm8.SymFunc:
return tast.NewRef(types.VoidFunc), sym
}
b.Errorf(m.Sub.Pos, "invalid symbol %s in %s: %s",
m.Sub.Lit, pkg, asm8.SymStr(sym.Type),
)
return nil, nil
}
t := sym.ObjType.(types.T)
switch sym.Type {
case tast.SymConst, tast.SymStruct, tast.SymFunc:
return tast.NewRef(t), sym
case tast.SymVar:
return tast.NewAddressableRef(t), sym
}
b.Errorf(m.Sub.Pos, "bug: invalid symbol %s in %s: %s",
m.Sub.Lit, pkg, tast.SymStr(sym.Type),
)
return nil, nil
}
func binaryOpInt(
b *builder, opTok *lex8.Token, A, B tast.Expr, t types.T,
) tast.Expr {
op := opTok.Lit
switch op {
case "+", "-", "*", "&", "|", "^", "%", "/":
r := tast.NewRef(t)
return &tast.OpExpr{A, opTok, B, r}
case "==", "!=", ">", "<", ">=", "<=":
r := tast.NewRef(types.Bool)
return &tast.OpExpr{A, opTok, B, r}
}
b.Errorf(opTok.Pos, "%q on ints", op)
return nil
}
func buildSlicing(
b *builder, expr *ast.IndexExpr, array tast.Expr,
) tast.Expr {
t := array.R().T
et := elementType(t)
if et == nil {
b.Errorf(expr.Lbrack.Pos, "slicing on neither array nor slice")
return nil
}
var indexStart, indexEnd tast.Expr
if expr.Index != nil {
indexStart = buildArrayIndex(b, expr.Index, expr.Lbrack.Pos)
if indexStart == nil {
return nil
}
}
if expr.IndexEnd != nil {
indexEnd = buildArrayIndex(b, expr.IndexEnd, expr.Colon.Pos)
if indexEnd == nil {
return nil
}
}
ref := tast.NewRef(&types.Slice{et})
return &tast.IndexExpr{
Array: array,
Index: indexStart,
IndexEnd: indexEnd,
HasColon: true,
Ref: ref,
}
}
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 buildConstMember(b *builder, m *ast.MemberExpr) tast.Expr {
obj := b.buildConstExpr(m.Expr)
if obj == nil {
return nil
}
ref := obj.R()
if !ref.IsSingle() {
b.Errorf(m.Dot.Pos, "%s does not have any member", ref)
return nil
}
if pkg, ok := ref.T.(*types.Pkg); ok {
s := findPackageSym(b, m.Sub, pkg)
if s == nil {
return nil
}
if s.Type != tast.SymConst {
b.Errorf(m.Sub.Pos, "%s.%s is not a const", pkg, m.Sub.Lit)
return nil
}
return &tast.Const{tast.NewRef(s.ObjType.(types.T))}
}
b.Errorf(m.Dot.Pos, "expect const expression")
return nil
}
func binaryOpSlice(b *builder, opTok *lex8.Token, A, B tast.Expr) tast.Expr {
op := opTok.Lit
switch op {
case "==", "!=":
return &tast.OpExpr{A, opTok, B, tast.NewRef(types.Bool)}
}
b.Errorf(opTok.Pos, "%q on slices", op)
return nil
}
func unaryOpBool(b *builder, opTok *lex8.Token, B tast.Expr) tast.Expr {
op := opTok.Lit
if op == "!" {
t := B.R().T
return &tast.OpExpr{nil, opTok, B, tast.NewRef(t)}
}
b.Errorf(opTok.Pos, "invalid operation: %q on boolean", op)
return nil
}
func binaryOpBool(b *builder, opTok *lex8.Token, A, B tast.Expr) tast.Expr {
op := opTok.Lit
switch op {
case "==", "!=", "&&", "||":
r := tast.NewRef(types.Bool)
return &tast.OpExpr{A, opTok, B, r}
}
b.Errorf(opTok.Pos, "%q on bools", op)
return nil
}
func buildMethod(b *builder, f *pkgFunc) *tast.Func {
this := f.recv.pt
b.thisType = this
if f.f.Recv != nil { // go-like, explicit receiver
b.this = tast.NewAddressableRef(this)
} else { // inlined
b.this = tast.NewRef(this)
b.scope.PushTable(f.recv.t.Syms)
defer b.scope.Pop()
}
return buildFunc(b, f)
}
func unaryOpInt(b *builder, opTok *lex8.Token, B tast.Expr) tast.Expr {
op := opTok.Lit
switch op {
case "+":
return B
case "-", "^":
t := B.R().T
return &tast.OpExpr{nil, opTok, B, tast.NewRef(t)}
}
b.Errorf(opTok.Pos, "invalid operation: %q on %s", op, B)
return nil
}
func buildCallLen(b *builder, expr *ast.CallExpr, f tast.Expr) tast.Expr {
args := buildExprList(b, expr.Args)
if args == nil {
return nil
}
ref := args.R()
if !ref.IsSingle() {
b.Errorf(expr.Lparen.Pos, "len() takes one argument")
return nil
}
t := ref.T
switch t.(type) {
case *types.Slice:
return &tast.CallExpr{f, args, tast.NewRef(types.Int)}
case *types.Array:
return &tast.CallExpr{f, args, tast.NewRef(types.Int)}
}
b.Errorf(expr.Lparen.Pos, "len() does not take %s", t)
return nil
}
func buildConstIdent(b *builder, ident *lex8.Token) tast.Expr {
s := b.scope.Query(ident.Lit)
if s == nil {
b.Errorf(ident.Pos, "undefined identifier %s", ident.Lit)
return nil
}
b.refSym(s, ident.Pos)
t := s.ObjType.(types.T)
switch s.Type {
case tast.SymConst:
ref := tast.NewRef(t)
return &tast.Const{ref}
case tast.SymStruct, tast.SymType, tast.SymImport:
ref := tast.NewRef(t)
return &tast.Ident{ident, ref, s}
}
b.Errorf(ident.Pos, "%s is a %s; expect a const",
ident.Lit, tast.SymStr(s.Type),
)
return nil
}
func refAddress(b *builder, opTok *lex8.Token, B tast.Expr) tast.Expr {
op := opTok.Lit
opPos := opTok.Pos
bref := B.R()
if types.IsType(bref.T) || !bref.IsSingle() {
b.Errorf(opPos, "%q on %s", op, bref)
return nil
} else if !bref.Addressable {
b.Errorf(opPos, "reading address of non-addressable")
return nil
}
r := tast.NewRef(&types.Pointer{bref.T})
return &tast.OpExpr{nil, opTok, B, r}
}
func binaryOpPtr(b *builder, opTok *lex8.Token, A, B tast.Expr) tast.Expr {
op := opTok.Lit
atyp := A.R().T
btyp := B.R().T
switch op {
case "==", "!=":
if types.IsNil(atyp) {
A = tast.NewCast(A, btyp)
} else if types.IsNil(btyp) {
B = tast.NewCast(B, atyp)
}
return &tast.OpExpr{A, opTok, B, tast.NewRef(types.Bool)}
}
b.Errorf(opTok.Pos, "%q on pointers", 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 buildMember(b *builder, m *ast.MemberExpr) tast.Expr {
obj := b.buildExpr(m.Expr)
if obj == nil {
return nil
}
ref := obj.R()
if !ref.IsSingle() {
b.Errorf(m.Dot.Pos, "%s does not have any member", ref)
return nil
}
t := ref.T
if pkg, ok := t.(*types.Pkg); ok {
r, sym := buildPkgSym(b, m, pkg)
if r == nil {
return nil
}
// TODO: this can be further optimized
return &tast.MemberExpr{obj, m.Sub, r, sym}
}
pt := types.PointerOf(t)
var tstruct *types.Struct
var ok bool
if pt != nil {
if tstruct, ok = pt.(*types.Struct); !ok {
b.Errorf(m.Dot.Pos, "*%s is not a pointer of struct", t)
return nil
}
} else {
if tstruct, ok = t.(*types.Struct); !ok {
b.Errorf(m.Dot.Pos, "%s is not a struct", t)
return nil
}
}
symTable := tstruct.Syms
name := m.Sub.Lit
sym := symTable.Query(name)
if sym == nil {
b.Errorf(m.Sub.Pos, "struct %s has no member named %s",
tstruct, name,
)
return nil
} else if !sym8.IsPublic(name) && sym.Pkg() != b.path {
b.Errorf(m.Sub.Pos, "symbol %s is not public", name)
return nil
}
b.refSym(sym, m.Sub.Pos)
if sym.Type == tast.SymField {
t := sym.ObjType.(types.T)
r := tast.NewAddressableRef(t)
return &tast.MemberExpr{obj, m.Sub, r, sym}
} else if sym.Type == tast.SymFunc {
ft := sym.ObjType.(*types.Func)
r := tast.NewRef(ft.MethodFunc)
r.Recv = ref
return &tast.MemberExpr{obj, m.Sub, r, sym}
}
b.Errorf(m.Sub.Pos, "invalid sym type: %s", tast.SymStr(sym.Type))
return nil
}
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 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}
}