Slightly better handling of SIGINT

internal/debug/repl.go

@@ -73,9 +73,17 @@ read_input:
 
  switch command {
  case "s", "step":
+ if ctx.Err() != nil {
+ r.println(`error: the module has exited. Try "restart", "quit" or "help"`)
+ goto read_input
+ }
  r.stepping = true
 
  case "c", "continue":
+ if ctx.Err() != nil {
+ r.println(`error: the module has exited. Try "restart", "quit" or "help"`)
+ goto read_input
+ }
  r.stepping = false
 
  case "r", "restart":
@@ -107,3 +115,7 @@ func (r *REPL) printf(s string, args ...any) (int, error) {
 func (r *REPL) print(args ...any) (int, error) {
  return fmt.Fprint(r.writer, args...)
 }
+
+func (r *REPL) println(args ...any) (int, error) {
+ return fmt.Fprintln(r.writer, args...)
+}

internal/debug/tracer.go

@@ -87,6 +87,7 @@ func (t *Tracer) ModuleBefore(ctx context.Context, mod wazero.CompiledModule) {
 }
 
 func (t *Tracer) ModuleAfter(ctx context.Context, err any) {
+ t.print("\n")
  switch e := err.(type) {
  case nil:
  t.print("The module exited normally\n")

main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
- "context"
  "io"
  "log"
  "os"
@@ -13,5 +12,5 @@ func init() {
 }
 
 func main() {
- os.Exit(root(context.Background(), os.Args[1:]...))
+ os.Exit(root(os.Args[1:]...))
 }

replay.go

@@ -85,7 +85,7 @@ func replay(ctx context.Context, args []string) error {
 
  var debugREPL *debug.REPL
  if debugger {
- debugREPL = debug.NewREPL(os.Stdin, os.Stdout)
+ debugREPL = debug.NewREPL(os.Stdin, os.Stderr)
  ctx = debug.RegisterFunctionListener(ctx, debugREPL)
  }
 

root.go

@@ -49,7 +49,7 @@ Example:
 For a list of commands available, run 'timecraft help'.`
 
 // root is the timecraft entrypoint.
-func root(ctx context.Context, args ...string) int {
+func root(args ...string) int {
  var (
  // Secret options, we don't document them since they are only used for
  // development. Since they are not part of the public interface we may
@@ -96,6 +96,8 @@ func root(ctx context.Context, args ...string) int {
  cmd, args := args[0], args[1:]
 
 run_command:
+ ctx := context.Background()
+
  var err error
  switch cmd {
  case "config":

run.go

@@ -93,7 +93,7 @@ func run(ctx context.Context, args []string) error {
 
  var debugREPL *debug.REPL
  if debugger {
- debugREPL = debug.NewREPL(os.Stdin, os.Stdout)
+ debugREPL = debug.NewREPL(os.Stdin, os.Stderr)
  ctx = debug.RegisterFunctionListener(ctx, debugREPL)
  }
 
@@ -227,9 +227,9 @@ func run(ctx context.Context, args []string) error {
 func instantiate(ctx context.Context, runtime wazero.Runtime, compiledModule wazero.CompiledModule, debugREPL *debug.REPL) (err error) {
  if debugREPL != nil {
  // The double defer is so that we can catch debug.{Quit,Restart}Error,
- // whether it originates from deep with the WebAssembly module
- // execution, or whether it originates from the OnEvent handler below
- // which is called after the module exits.
+ // whether it originates from deep within the WebAssembly module, or
+ // whether it originates from the OnEvent handler below which is called
+ // after the module exits.
  defer func() {
  defer func() {
  switch e := recover(); e {
@@ -243,10 +243,11 @@ func instantiate(ctx context.Context, runtime wazero.Runtime, compiledModule waz
  }
  }()
 
- e := recover()
- debugREPL.OnEvent(ctx, &debug.ModuleAfterEvent{Error: e})
- if e != nil {
- panic(e)
+ if panicErr := recover(); panicErr != nil {
+ debugREPL.OnEvent(ctx, &debug.ModuleAfterEvent{Error: panicErr})
+ panic(panicErr)
+ } else {
+ debugREPL.OnEvent(ctx, &debug.ModuleAfterEvent{Error: err})
  }
  }()