Ensure temp files and other resources are cleaned up even if kitty crashes or is SIGKILLed

tools/cmd/atexit/main.go

@@ -2,12 +2,15 @@ package atexit
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
+	"io/fs"
 	"os"
 	"os/signal"
 	"strings"
 
 	"kitty/tools/cli"
+	"kitty/tools/utils/shm"
 )
 
 var _ = fmt.Print
@@ -40,13 +43,18 @@ func main() (rc int, err error) {
 		if action, rest, found := strings.Cut(line, " "); found {
 			switch action {
 			case "unlink":
-				if err := os.Remove(rest); err != nil {
-					fmt.Fprintln(os.Stderr, "Failed to remove:", rest, "with error:", err)
+				if err := os.Remove(rest); err != nil && !errors.Is(err, fs.ErrNotExist) {
+					fmt.Fprintln(os.Stderr, "Failed to unlink:", rest, "with error:", err)
+					rc = 1
+				}
+			case "shm_unlink":
+				if err := shm.ShmUnlink(rest); err != nil && !errors.Is(err, fs.ErrNotExist) {
+					fmt.Fprintln(os.Stderr, "Failed to shm_unlink:", rest, "with error:", err)
 					rc = 1
 				}
 			case "rmtree":
-				if err := os.RemoveAll(rest); err != nil {
-					fmt.Fprintln(os.Stderr, "Failed to remove:", rest, "with error:", err)
+				if err := os.RemoveAll(rest); err != nil && !errors.Is(err, fs.ErrNotExist) {
+					fmt.Fprintln(os.Stderr, "Failed to rmtree:", rest, "with error:", err)
 					rc = 1
 				}
 			}

tools/utils/shm/shm_fs.go

@@ -12,6 +12,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 
 	"kitty/tools/utils"
 
@@ -28,6 +29,16 @@ type file_based_mmap struct {
 	special_name string
 }
 
+func ShmUnlink(name string) error {
+	if runtime.GOOS == "openbsd" {
+		return os.Remove(openbsd_shm_path(name))
+	}
+	if strings.HasPrefix(name, "/") {
+		name = name[1:]
+	}
+	return os.Remove(filepath.Join(SHM_DIR, name))
+}
+
 func file_mmap(f *os.File, size uint64, access AccessFlags, truncate bool, special_name string) (MMap, error) {
 	if truncate {
 		err := truncate_or_unlink(f, size, os.Remove)
@@ -106,11 +117,15 @@ func (self *file_based_mmap) Unlink() (err error) {
 
 func (self *file_based_mmap) IsFileSystemBacked() bool { return true }
 
+func openbsd_shm_path(name string) string {
+	hash := sha256.Sum256(utils.UnsafeStringToBytes(name))
+	return filepath.Join(SHM_DIR, utils.UnsafeBytesToString(hash[:])+".shm")
+}
+
 func file_path_from_name(name string) string {
 	// See https://github.com/openbsd/src/blob/master/lib/libc/gen/shm_open.c
 	if runtime.GOOS == "openbsd" {
-		hash := sha256.Sum256(utils.UnsafeStringToBytes(name))
-		return filepath.Join(SHM_DIR, utils.UnsafeBytesToString(hash[:])+".shm")
+		return openbsd_shm_path(name)
 	}
 	return filepath.Join(SHM_DIR, name)
 }

tools/utils/shm/shm_syscall.go

@@ -37,7 +37,11 @@ func shm_unlink(name string) (err error) {
 		_, _, errno := unix.Syscall(unix.SYS_SHM_UNLINK, uintptr(unsafe.Pointer(bname)), 0, 0)
 		if errno != unix.EINTR {
 			if errno != 0 {
-				err = fmt.Errorf("shm_unlink() failed with error: %w", errno)
+				if errno == unix.ENOENT {
+					err = fs.ErrNotExist
+				} else {
+					err = fmt.Errorf("shm_unlink() failed with error: %w", errno)
+				}
 			}
 			break
 		}
@@ -45,6 +49,10 @@ func shm_unlink(name string) (err error) {
 	return
 }
 
+func ShmUnlink(name string) error {
+	return shm_unlink(name)
+}
+
 func shm_open(name string, flags, perm int) (ans *os.File, err error) {
 	bname := BytePtrFromString(name)
 	var fd uintptr