fmsg: implement suspend in writer

This removes the requirement to call fmsg.Exit on every exit path, and enables direct use of the "log" package. However, fmsg.BeforeExit is still encouraged when possible to catch exit on suspended output.

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

cmd/fpkg/proc.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"errors"
 	"io"
+	"log"
 	"os"
 	"os/exec"
 
@@ -25,14 +26,12 @@ func fortifyApp(config *fst.Config, beforeFail func()) {
 	)
 	if p, ok := internal.Path(Fmain); !ok {
 		beforeFail()
-		fmsg.Fatal("invalid fortify path, this copy of fpkg is not compiled correctly")
-		panic("unreachable")
+		log.Fatal("invalid fortify path, this copy of fpkg is not compiled correctly")
 	} else if r, w, err := os.Pipe(); err != nil {
 		beforeFail()
-		fmsg.Fatalf("cannot pipe: %v", err)
-		panic("unreachable")
+		log.Fatalf("cannot pipe: %v", err)
 	} else {
-		if fmsg.Verbose() {
+		if fmsg.Load() {
 			cmd = exec.Command(p, "-v", "app", "3")
 		} else {
 			cmd = exec.Command(p, "app", "3")
@@ -45,26 +44,22 @@ func fortifyApp(config *fst.Config, beforeFail func()) {
 	go func() {
 		if err := json.NewEncoder(st).Encode(config); err != nil {
 			beforeFail()
-			fmsg.Fatalf("cannot send configuration: %v", err)
-			panic("unreachable")
+			log.Fatalf("cannot send configuration: %v", err)
 		}
 	}()
 
 	if err := cmd.Start(); err != nil {
 		beforeFail()
-		fmsg.Fatalf("cannot start fortify: %v", err)
-		panic("unreachable")
+		log.Fatalf("cannot start fortify: %v", err)
 	}
 	if err := cmd.Wait(); err != nil {
 		var exitError *exec.ExitError
 		if errors.As(err, &exitError) {
 			beforeFail()
-			fmsg.Exit(exitError.ExitCode())
-			panic("unreachable")
+			internal.Exit(exitError.ExitCode())
 		} else {
 			beforeFail()
-			fmsg.Fatalf("cannot wait: %v", err)
-			panic("unreachable")
+			log.Fatalf("cannot wait: %v", err)
 		}
 	}
 }