prog: simplify code

Now that we don't have ReturnArg and only ResultArg's refer
to other ResultArg's we can remove ArgUser/ArgUsed and
devirtualize lots of code.

1 files changed, 13 insertions, 16 deletions

diff --git a/prog/clone.go b/prog/clone.go
index e7d937318..51d801e28 100644
--- a/prog/clone.go
+++ b/prog/clone.go
@@ -8,11 +8,11 @@ func (p *Prog) Clone() *Prog {
 		Target: p.Target,
 		Calls:  make([]*Call, len(p.Calls)),
 	}
-	newargs := make(map[Arg]Arg)
+	newargs := make(map[*ResultArg]*ResultArg)
 	for ci, c := range p.Calls {
 		c1 := new(Call)
 		c1.Meta = c.Meta
-		c1.Ret = clone(c.Ret, newargs)
+		c1.Ret = clone(c.Ret, newargs).(*ResultArg)
 		c1.Args = make([]Arg, len(c.Args))
 		for ai, arg := range c.Args {
 			c1.Args[ai] = clone(arg, newargs)
@@ -27,7 +27,7 @@ func (p *Prog) Clone() *Prog {
 	return p1
 }
 
-func clone(arg Arg, newargs map[Arg]Arg) Arg {
+func clone(arg Arg, newargs map[*ResultArg]*ResultArg) Arg {
 	var arg1 Arg
 	switch a := arg.(type) {
 	case *ConstArg:
@@ -63,21 +63,18 @@ func clone(arg Arg, newargs map[Arg]Arg) Arg {
 		a1 := new(ResultArg)
 		*a1 = *a
 		arg1 = a1
+		if a1.Res != nil {
+			r := newargs[a1.Res]
+			a1.Res = r
+			if r.uses == nil {
+				r.uses = make(map[*ResultArg]bool)
+			}
+			r.uses[a1] = true
+		}
+		a1.uses = nil // filled when we clone the referent
+		newargs[a] = a1
 	default:
 		panic("bad arg kind")
 	}
-	if user, ok := arg1.(ArgUser); ok && *user.Uses() != nil {
-		r := newargs[*user.Uses()]
-		*user.Uses() = r
-		used := r.(ArgUsed)
-		if *used.Used() == nil {
-			*used.Used() = make(map[Arg]bool)
-		}
-		(*used.Used())[arg1] = true
-	}
-	if used, ok := arg1.(ArgUsed); ok {
-		*used.Used() = nil // filled when we clone the referent
-		newargs[arg] = arg1
-	}
 	return arg1
 }