func regSizeCastable(to, from types.T) bool {
if types.IsPointer(to) && types.IsPointer(from) {
return true
}
if isPointerType(to) && types.IsBasic(from, types.Uint) {
return true
}
if types.IsBasic(to, types.Uint) && isPointerType(from) {
return true
}
return false
}
func buildUnaryOpExpr(b *builder, expr *ast.OpExpr) tast.Expr {
opTok := expr.Op
op := opTok.Lit
opPos := opTok.Pos
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 op == "&" {
return refAddress(b, opTok, B)
} else if types.IsConst(btyp) {
return unaryOpConst(b, opTok, B)
} else if types.IsInteger(btyp) {
return unaryOpInt(b, opTok, B)
} else if types.IsBasic(btyp, types.Bool) {
return unaryOpBool(b, opTok, B)
}
b.Errorf(opPos, "invalid unary operator %q", op)
return nil
}
func makeArg(t *types.Arg) *ir.FuncArg {
return &ir.FuncArg{
Name: t.Name,
Size: t.Size(),
U8: types.IsBasic(t.T, types.Uint8),
RegSizeAlign: t.RegSizeAlign(),
}
}
func buildStarExpr(b *builder, expr *tast.StarExpr) *ref {
addr := b.buildExpr(expr.Expr)
nilPointerPanic(b, addr.IR())
t := addr.Type().(*types.Pointer).T
retIR := ir.NewAddrRef(
addr.IR(), // base
t.Size(), // size
0, // offset
types.IsBasic(t, types.Uint8), // is byte?
t.RegSizeAlign(), // is aligned?
)
return newAddressableRef(t, retIR)
}
func buildBinaryOpExpr(b *builder, expr *tast.OpExpr) *ref {
op := expr.Op.Lit
A := b.buildExpr(expr.A)
atyp := A.Type()
if types.IsBasic(atyp, types.Bool) && (op == "&&" || op == "||") {
switch op {
case "&&":
return buildLogicAnd(b, A, expr.B)
case "||":
return buildLogicOr(b, A, expr.B)
}
panic("unreachable")
}
B := b.buildExpr(expr.B)
btyp := B.Type()
if types.IsConst(atyp) && types.IsConst(btyp) {
return binaryOpConst(b, op, A, B)
}
if op == ">>" || op == "<<" {
ret := b.newTemp(atyp)
buildShift(b, ret, A, B, op)
return ret
}
if ok, t := types.SameBasic(atyp, btyp); ok {
switch t {
case types.Int, types.Int8:
return binaryOpInt(b, op, A, B, t)
case types.Uint, types.Uint8:
return binaryOpUint(b, op, A, B, t)
case types.Bool:
return binaryOpBool(b, op, A, B)
}
panic("bug")
}
if types.IsNil(atyp) && types.IsNil(btyp) {
return binaryOpNil(b, op, A, B)
} else if types.BothPointer(atyp, btyp) {
return binaryOpPtr(b, op, A, B)
} else if types.BothFuncPointer(atyp, btyp) {
return binaryOpPtr(b, op, A, B)
} else if types.BothSlice(atyp, btyp) {
return binaryOpSlice(b, op, A, B)
}
panic("bug")
}
func buildUnaryOpExpr(b *builder, expr *tast.OpExpr) *ref {
op := expr.Op.Lit
B := b.buildExpr(expr.B)
btyp := B.Type()
if op == "&" {
ret := b.newTemp(&types.Pointer{btyp})
b.b.Arith(ret.IR(), nil, op, B.IR())
return ret
} else if types.IsConst(btyp) {
panic("bug")
} else if types.IsInteger(btyp) {
return unaryOpInt(b, op, B)
} else if types.IsBasic(btyp, types.Bool) {
return unaryOpBool(b, op, B)
}
panic("bug")
}
// IsBool checks if the ref is a single boolean ref.
func (r *Ref) IsBool() bool {
return r.IsSingle() && types.IsBasic(r.Type(), types.Bool)
}
func (r *ref) IsBool() bool {
if !r.IsSingle() {
return false
}
return types.IsBasic(r.Type(), types.Bool)
}
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
}