prog: move all flag mutation logic into flags() (#1362)

This makes it a bit easier to understand.

Also fix an issue with using flag value as bit number.

1 files changed, 1 insertions, 21 deletions

diff --git a/prog/mutation.go b/prog/mutation.go
index 8a33c3e2e..6c356c4b4 100644
--- a/prog/mutation.go
+++ b/prog/mutation.go
@@ -236,29 +236,9 @@ func (t *IntType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Ca
 
 func (t *FlagsType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []*Call, retry, preserve bool) {
 	a := arg.(*ConstArg)
-
 	for oldVal := a.Val; oldVal == a.Val; {
-		// Generate a new value.
-		if r.nOutOf(1, 5) {
-			a.Val = r.flags(t.Vals, t.BitMask, 0)
-			continue
-		}
-
-		if !t.BitMask || (t.BitMask && r.nOutOf(1, 4)) {
-			a.Val = r.flags(t.Vals, t.BitMask, a.Val)
-			continue
-		}
-
-		for stop := false; !stop; stop = r.oneOf(3) {
-			idx := r.rand(len(t.Vals))
-			if r.bin() {
-				a.Val |= 1 << t.Vals[idx]
-			} else {
-				a.Val &= ^(1 << t.Vals[idx])
-			}
-		}
+		a.Val = r.flags(t.Vals, t.BitMask, a.Val)
 	}
-
 	return
 }