acme-lsp: add Restart verb to /LSP/Diagnostics

When working on acme-lsp, it is convenient to be able
to go install a new acme-lsp and then have a way to restart it.

This change adds a new Restart action in /LSP/Diagnostics
to re-exec the current acme-lsp.

internal/lsp/acmelsp/diagnostics.go

@@ -2,7 +2,10 @@ package acmelsp
 
 import (
  "fmt"
+ "log"
+ "os"
  "sync"
+ "syscall"
  "time"
 
  "github.com/fhs/acme-lsp/internal/acmeutil"
@@ -72,6 +75,9 @@ func (dw *diagWin) restart() error {
  case "Reload":
  dw.updateChan <- struct{}{}
  continue
+
+ case "Restart":
+ restart()
  }
  }
  dw.WriteEvent(ev)
@@ -136,3 +142,12 @@ func NewDiagnosticsWriter() DiagnosticsWriter {
  }()
  return dw
 }
+
+func restart() {
+ exe, err := os.Executable()
+ if err != nil {
+ exe = os.Args[0]
+ }
+ err = syscall.Exec(exe, os.Args, os.Environ())
+ log.Fatalf("exec: %v", err)
+}