cmd/mbf: garbage collection commands

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -86,6 +86,7 @@ func main() {
 		flagCheck bool
 		flagLTO   bool
 		flagPT    bool
+		flagDry   bool
 
 		flagSourcePath    string
 		flagCrossOverride int
@@ -204,6 +205,10 @@ func main() {
 		&flagPT,
 		"parse-time", command.BoolFlag(false),
 		"Print duration of the initial azalea parse",
+	).Flag(
+		&flagDry,
+		"dry", command.BoolFlag(false),
+		"Do not destroy cache entries",
 	).Flag(
 		&flagSourcePath,
 		"source", command.StringFlag(""),
@@ -736,8 +741,9 @@ func main() {
 		)
 	}
 
-	c.NewCommand(
+	cleanC := c.New("clean", "Remove unused entries from the cache")
-		"clear",
+	cleanC.NewCommand(
+		"fault",
 		"Remove all fault entries from the cache",
 		func([]string) error {
 			return cm.Do(func(*pkg.Cache) error {
@@ -758,6 +764,43 @@ func main() {
 			})
 		},
 	)
+	cleanC.NewCommand(
+		"checksum",
+		"Remove unreachable checksum entries",
+		func([]string) error {
+			return cm.Do(func(cache *pkg.Cache) error {
+				_, checksums, err := cache.Clean(flagDry, false)
+				log.Printf("destroyed %d entries", len(checksums))
+				return err
+			})
+		},
+	)
+	{
+		var flagDeep bool
+		cleanC.NewCommand(
+			"all",
+			"Remove identifiers not reachable by loaded packages",
+			func([]string) error {
+				return cm.Do(func(cache *pkg.Cache) error {
+					t := rosa.Native().Std()
+					ids, checksums, err := cache.Clean(
+						flagDry,
+						!flagDeep,
+						t.Append(nil, t.CollectAll()...)...,
+					)
+					log.Printf(
+						"destroyed %d identifier and %d checksum entries",
+						len(ids), len(checksums),
+					)
+					return err
+				})
+			},
+		).Flag(
+			&flagDeep,
+			"deep", command.BoolFlag(false),
+			"Include transitive inputs",
+		)
+	}
 
 	c.NewCommand(
 		"abort",