Catch empty code after engine init

dev/interactive/main.go

@@ -22,10 +22,14 @@ func main() {
 	fmt.Fprintf(os.Stderr, "starting session at symbol '%s' using resource dir: %s\n", root, dir)
 
 	ctx := context.Background()
-	en := engine.NewSizedEngine(dir, uint32(size))
+	en, err := engine.NewSizedEngine(dir, uint32(size))
-	err := engine.Loop(&en, os.Stdin, os.Stdout, ctx)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "loop exited with error: %v", err)
+		fmt.Fprintf(os.Stderr, "engine create fail: %v\n", err)
+		os.Exit(1)
+	}
+	err = engine.Loop(&en, os.Stdin, os.Stdout, ctx)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "loop exited with error: %v\n", err)
 		os.Exit(1)
 	}
 }

engine/default.go

@@ -9,7 +9,7 @@ import (
 )
 
 // NewDefaultEngine is a convenience function to instantiate a filesystem-backed engine with no output constraints.
-func NewDefaultEngine(dir string) Engine {
+func NewDefaultEngine(dir string) (Engine, error) {
 	st := state.NewState(0)
 	rs := resource.NewFsResource(dir)
 	ca := cache.NewCache()
@@ -21,7 +21,7 @@ func NewDefaultEngine(dir string) Engine {
 }
 
 // NewSizedEngine is a convenience function to instantiate a filesystem-backed engine with a specified output constraint.
-func NewSizedEngine(dir string, size uint32) Engine {
+func NewSizedEngine(dir string, size uint32) (Engine, error) {
 	st := state.NewState(0)
 	rs := resource.NewFsResource(dir)
 	ca := cache.NewCache()

engine/engine.go

@@ -32,7 +32,7 @@ type Engine struct {
 }
 
 // NewEngine creates a new Engine
-func NewEngine(cfg Config, st *state.State, rs resource.Resource, ca cache.Memory, ctx context.Context) Engine {
+func NewEngine(cfg Config, st *state.State, rs resource.Resource, ca cache.Memory, ctx context.Context) (Engine, error) {
 	var szr *render.Sizer
 	if cfg.OutputSize > 0 {
 		szr = render.NewSizer(cfg.OutputSize)
@@ -44,10 +44,11 @@ func NewEngine(cfg Config, st *state.State, rs resource.Resource, ca cache.Memor
 		ca: ca,
 		vm: vm.NewVm(st, rs, ca, szr),
 	}
+	var err error
 	if st.Moves == 0 {
-		engine.Init(cfg.Root, ctx)
+		err = engine.Init(cfg.Root, ctx)
 	}
-	return engine
+	return engine, err
 }
 
 // Init must be explicitly called before using the Engine instance.
@@ -71,6 +72,9 @@ func(en *Engine) Init(sym string, ctx context.Context) error {
 	if err != nil {
 		return err
 	}
+	if len(b) == 0 {
+		return fmt.Errorf("no code left after init, that's just useless and sad")
+	}
 	log.Printf("ended init VM run with code %x", b)
 	en.st.SetCode(b)
 	en.initd = true

engine/engine_test.go

@@ -81,9 +81,12 @@ func TestEngineInit(t *testing.T) {
 	rs := NewFsWrapper(dataDir, &st)
 	ca := cache.NewCache().WithCacheSize(1024)
 	
-	en := NewEngine(Config{
+	en, err := NewEngine(Config{
 		Root: "root",
 	}, &st, &rs, ca, ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
 //
 	w := bytes.NewBuffer(nil)
 	_, err = en.WriteResult(w, ctx)
@@ -133,8 +136,14 @@ func TestEngineExecInvalidInput(t *testing.T) {
 	rs := NewFsWrapper(dataDir, &st)
 	ca := cache.NewCache().WithCacheSize(1024)
 
-	en := NewEngine(Config{}, &st, &rs, ca, ctx)
+	
-	err := en.Init("root", ctx)
+	en, err := NewEngine(Config{
+		Root: "root",
+	}, &st, &rs, ca, ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = en.Init("root", ctx)
 	if err != nil {
 		t.Fatal(err)
 	}

engine/loop_test.go

@@ -23,8 +23,11 @@ func TestLoopTop(t *testing.T) {
 	cfg := Config{
 		Root: "root",
 	}
-	en := NewEngine(cfg, &st, &rs, ca, ctx)
+	en, err := NewEngine(cfg, &st, &rs, ca, ctx)
-	err := en.Init("root", ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = en.Init("root", ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -59,8 +62,11 @@ func TestLoopBackForth(t *testing.T) {
 	cfg := Config{
 		Root: "root",
 	}
-	en := NewEngine(cfg, &st, &rs, ca, ctx)
+	en, err := NewEngine(cfg, &st, &rs, ca, ctx)
-	err := en.Init("root", ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = en.Init("root", ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -93,8 +99,11 @@ func TestLoopBrowse(t *testing.T) {
 		OutputSize: 68,
 		Root: "root",
 	}
-	en := NewEngine(cfg, &st, &rs, ca, ctx)
+	en, err := NewEngine(cfg, &st, &rs, ca, ctx)
-	err := en.Init("root", ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = en.Init("root", ctx)
 	if err != nil {
 		t.Fatal(err)
 	}

engine/persist.go

@@ -24,7 +24,10 @@ func RunPersisted(cfg Config, rs resource.Resource, pr persist.Persister, input
 		return err
 	}
 
-	en := NewEngine(cfg, pr.GetState(), rs, pr.GetMemory(), ctx)
+	en, err := NewEngine(cfg, pr.GetState(), rs, pr.GetMemory(), ctx)
+	if err != nil {
+		return err
+	}
 
 	c, err := en.WriteResult(w, ctx)
 	if err != nil {

examples/profile/main.go

@@ -17,6 +17,10 @@ import (
 	"git.defalsify.org/vise/state"
 )
 
+const (
+	USERFLAG_IDENTIFIED = iota + state.FLAG_USERSTART
+)
+
 var (
 	baseDir = testdataloader.GetBasePath()
 	scriptDir = path.Join(baseDir, "examples", "profile")
@@ -47,7 +51,7 @@ func main() {
 	flag.Parse()
 	fmt.Fprintf(os.Stderr, "starting session at symbol '%s' using resource dir: %s\n", root, dir)
 
-	st := state.NewState(0)
+	st := state.NewState(1)
 	rs := resource.NewFsResource(scriptDir)
 	rs.AddLocalFunc("do_name_save", nameSave)
 	rs.AddLocalFunc("do_email_save", emailSave)
@@ -58,11 +62,15 @@ func main() {
 		OutputSize: uint32(size),
 	}
 	ctx := context.Background()
-	en := engine.NewEngine(cfg, &st, &rs, ca, ctx)
+	en, err := engine.NewEngine(cfg, &st, &rs, ca, ctx)
-
-	err := engine.Loop(&en, os.Stdin, os.Stdout, ctx)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "loop exited with error: %v", err)
+		fmt.Fprintf(os.Stderr, "engine create fail: %v\n", err)
+		os.Exit(1)
+	}
+
+	err = engine.Loop(&en, os.Stdin, os.Stdout, ctx)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "loop exited with error: %v\n", err)
 		os.Exit(1)
 	}
 }

examples/profile/root.vis

@@ -1,3 +1,3 @@
+CATCH identified 9 0
 DOWN entry_name 0 "name"
 DOWN entry_email 1 "email"
-DOWN entry_sex 2 "sex"

state/flag.go

@@ -6,6 +6,7 @@ const (
 	FLAG_TERMINATE = 3
 	FLAG_DIRTY = 4
 	FLAG_LOADFAIL = 5
+	FLAG_USERSTART = 9
 	//FLAG_WRITEABLE = FLAG_LOADFAIL
 )
 

vm/runner.go

@@ -178,6 +178,11 @@ func(vm *Vm) RunCatch(b []byte, ctx context.Context) ([]byte, error) {
 	}
 	r, err := vm.st.MatchFlag(sig, mode)
 	if err != nil {
+		_, err = vm.st.SetFlag(state.FLAG_TERMINATE)
+		if err != nil {
+			panic(err)
+		}
+		log.Printf("terminate set")
 		return b, err
 	}
 	if r {