More simplifying: address is always known

asm/asm.go

@@ -184,11 +184,7 @@ func (a *Assembler) readMacro(in inst.I, ls lines.LineSource) error {
 func (a *Assembler) initPass() {
 	a.Flavor.SetLastLabel("") // No last label (yet)
 	a.Flavor.RemoveChanged()  // Remove any variables whose value ever changed.
-	if org, err := a.Flavor.DefaultOrigin(); err == nil {
-		a.Flavor.SetAddr(org)
-	} else {
-		a.Flavor.ClearAddr("beginning of assembly")
-	}
+	a.Flavor.SetAddr(a.Flavor.DefaultOrigin())
 }
 
 // passInst performs a pass on a single instruction. It forces the
@@ -204,17 +200,9 @@ func (a *Assembler) passInst(in *inst.I, final bool) (isFinal bool, err error) {
 	}
 
 	// Update address
-	if a.Flavor.AddrKnown() {
-		addr, _ := a.Flavor.GetAddr()
-		in.Addr = addr
-		in.AddrKnown = true
-
-		if in.WidthKnown {
-			a.Flavor.SetAddr(addr + in.Width)
-		} else {
-			a.Flavor.ClearAddr(in.Sprintf("lost known address"))
-		}
-	}
+	addr, _ := a.Flavor.GetAddr()
+	in.Addr = addr
+	a.Flavor.SetAddr(addr + in.Width)
 
 	return isFinal, nil
 }
@@ -267,9 +255,6 @@ func (a *Assembler) Membuf() (*membuf.Membuf, error) {
 		if !in.Final {
 			return nil, in.Errorf("cannot finalize value: %s", in)
 		}
-		if !in.AddrKnown {
-			return nil, in.Errorf("address unknown: %s", in)
-		}
 		if in.Width > 0 {
 			m.Write(int(in.Addr), in.Data)
 		}
@@ -282,9 +267,6 @@ func (a *Assembler) GenerateListing(w io.Writer, width int) error {
 		if !in.Final {
 			return in.Errorf("cannot finalize value: %s", in)
 		}
-		if !in.AddrKnown {
-			return in.Errorf("address unknown: %s", in)
-		}
 
 		for i := 0; i < len(in.Data) || i < width; i++ {
 			if i%width == 0 {

asm/context/context.go

@@ -11,7 +11,6 @@ type Context interface {
 	GetAddr() (uint16, bool)
 	Zero() (uint16, error) // type ZeroFunc
 	RemoveChanged()
-	AddrKnown() bool
 	Clear()
 	SettingOn(name string) error
 	SettingOff(name string) error
@@ -76,10 +75,6 @@ func (sc *SimpleContext) GetAddr() (uint16, bool) {
 	return uint16(sc.addr), true
 }
 
-func (sc *SimpleContext) AddrKnown() bool {
-	return sc.addr != -1
-}
-
 func (sc *SimpleContext) Set(name string, value uint16) {
 	sc.fix()
 	s, found := sc.symbols[name]

asm/expr/expression.go

@@ -118,11 +118,6 @@ func (e *E) Eval(ctx context.Context, ln *lines.Line) (uint16, error) {
 		if val, ok := ctx.Get(e.Text); ok {
 			return val, nil
 		}
-		if e.Text == "*" && !ctx.AddrKnown() {
-			e := ln.Errorf("address unknown due to %v", ctx.ClearMesg())
-			return 0, UnknownLabelError{Err: e}
-
-		}
 		return 0, UnknownLabelError{Err: ln.Errorf("unknown label: %s", e.Text)}
 	case OpMinus:
 		l, err := e.Left.Eval(ctx, ln)

asm/flavors/as65/as65.go

@@ -29,8 +29,8 @@ func (a *AS65) Zero() (uint16, error) {
 	return 0, errors.New("Division by zero.")
 }
 
-func (a *AS65) DefaultOrigin() (uint16, error) {
-	return 0, nil
+func (a *AS65) DefaultOrigin() uint16 {
+	return 0
 }
 
 func (a *AS65) ReplaceMacroArgs(line string, args []string, kwargs map[string]string) (string, error) {

asm/flavors/flavors.go

@@ -8,7 +8,7 @@ import (
 
 type F interface {
 	ParseInstr(Line lines.Line) (inst.I, error)
-	DefaultOrigin() (uint16, error)
+	DefaultOrigin() uint16
 	ReplaceMacroArgs(line string, args []string, kwargs map[string]string) (string, error)
 	LocalMacroLabels() bool
 	String() string

asm/flavors/merlin/merlin.go

@@ -160,8 +160,8 @@ func (m *Merlin) Zero() (uint16, error) {
 	return 0, errors.New("Division by zero.")
 }
 
-func (m *Merlin) DefaultOrigin() (uint16, error) {
-	return 0x8000, nil
+func (m *Merlin) DefaultOrigin() uint16 {
+	return 0x8000
 }
 
 func (m *Merlin) ParseInclude(in inst.I, lp *lines.Parse) (inst.I, error) {

asm/flavors/oldschool/oldschool.go

@@ -129,8 +129,8 @@ func (a *Base) ParseInstr(line lines.Line) (inst.I, error) {
 	return a.ParseCmd(in, lp)
 }
 
-func (a *Base) DefaultOrigin() (uint16, error) {
-	return 0x0800, nil
+func (a *Base) DefaultOrigin() uint16 {
+	return 0x0800
 }
 
 // ParseCmd parses the "command" part of an instruction: we expect to be

asm/inst/instruction.go

@@ -73,7 +73,6 @@ type I struct {
 	DeclaredLine uint16                 // Line number listed in file
 	Line         *lines.Line            // Line object for this line
 	Addr         uint16                 // Current memory address
-	AddrKnown    bool                   // Whether the current memory address is known
 	Var          int                    // Variant of instruction type
 }