"cmd/go/internal/trace"
	"cmd/internal/buildid"
	"cmd/internal/quoted"
	"cmd/internal/sys"
)

const DefaultCFlags = "-O2 -g"

// actionList returns the list of actions in the dag rooted at root
// as visited in a depth-first post-order traversal.
func actionList(root *Action) []*Action {
	seen := map[*Action]bool{}
	all := []*Action{}
	var walk func(*Action)
	walk = func(a *Action) {
		if seen[a] {
			return