diff --git a/version/cmdname.go b/version/cmdname.go index 5a0b84875..8e6adb047 100644 --- a/version/cmdname.go +++ b/version/cmdname.go @@ -13,6 +13,7 @@ import ( "os" "path" "runtime" + "runtime/debug" "strings" ) @@ -20,6 +21,15 @@ import ( // using os.Executable. If os.Executable fails (it shouldn't), then // "cmd" is returned. func CmdName() string { + // On non-Windows, the modinfo embedded in the running binary is + // authoritative and avoids re-reading the executable from disk. + // Windows needs the executable-name-based GUI override in cmdName, + // so it still takes the slower path. + if runtime.GOOS != "windows" { + if info, ok := debug.ReadBuildInfo(); ok && info.Path != "" { + return path.Base(info.Path) + } + } e, err := os.Executable() if err != nil { return "cmd" diff --git a/version/version_test.go b/version/version_test.go index 42bcf2163..01fcd47ec 100644 --- a/version/version_test.go +++ b/version/version_test.go @@ -6,6 +6,8 @@ package version_test import ( "bytes" "os" + "path" + "runtime/debug" "testing" ts "tailscale.com" @@ -49,3 +51,21 @@ func TestShortAllocs(t *testing.T) { t.Errorf("allocs = %v; want 0", allocs) } } + +func BenchmarkCmdName(b *testing.B) { + b.ReportAllocs() + for b.Loop() { + _ = version.CmdName() + } +} + +func BenchmarkReadBuildInfo(b *testing.B) { + b.ReportAllocs() + for b.Loop() { + info, ok := debug.ReadBuildInfo() + if !ok { + b.Fatal("ReadBuildInfo failed") + } + _ = path.Base(info.Path) + } +}