func printOp(p io.Writer, op op) {
switch op := op.(type) {
case *comment:
fmt.Fprintf(p, "// %s\n", op.s)
case *arithOp:
if op.a == nil {
if op.op == "" {
fmt.Fprintf(p, "%s = %s\n", op.dest, op.b)
} else if op.op == "0" {
fmt.Fprintf(p, "%s = 0\n", op.dest)
} else {
fmt.Fprintf(p, "%s = %s %s\n", op.dest, op.op, op.b)
}
} else {
fmt.Fprintf(p, "%s = %s %s %s\n",
op.dest, op.a, op.op, op.b,
)
}
case *callOp:
var args string
if op.args != nil {
args = fmt8.Join(op.args, ",")
}
fmt.Fprintf(p, "%s = %s(%s)\n", op.dest, op.f, args)
default:
panic(fmt.Errorf("invalid or unknown IR op: %T", op))
}
}
func (r *Ref) String() string {
if r == nil {
return "<error>"
}
if r.Void {
return "void"
}
if len(r.List) == 0 {
return r.T.String()
}
return fmt8.Join(r.List, ",")
}
func (r *ref) String() string {
if r == nil {
return "void"
}
if len(r.lst) == 0 {
if r.typ == nil {
return "<nil>"
}
return r.typ.String()
}
return fmt8.Join(r.TypeList(), ",")
}
// String returns the function signature (without the argument names).
func (t *Func) String() string {
// TODO: this is kind of ugly, need some refactoring
buf := new(bytes.Buffer)
fmt.Fprintf(buf, "func (%s)", fmt8.Join(t.Args, ","))
if len(t.Rets) > 1 {
fmt.Fprintf(buf, " (")
for i, ret := range t.Rets {
if i > 0 {
fmt.Fprint(buf, ",")
}
fmt.Fprint(buf, ret)
}
fmt.Fprint(buf, ")")
} else if len(t.Rets) == 1 {
fmt.Fprint(buf, " ")
fmt.Fprint(buf, t.Rets[0])
}
if t.IsBond {
fmt.Fprint(buf, " (bond)")
}
return buf.String()
}
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 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}
}