1 files changed, 30 insertions, 0 deletions
diff --git a/libgo/go/os/error.go b/libgo/go/os/error.go
index c3dd06feb7b..e0b83b5c22c 100644
--- a/libgo/go/os/error.go
+++ b/libgo/go/os/error.go
@@ -4,6 +4,18 @@
 
 package os
 
+import (
+	"errors"
+)
+
+// Portable analogs of some common system call errors.
+var (
+	ErrInvalid    = errors.New("invalid argument")
+	ErrPermission = errors.New("permission denied")
+	ErrExist      = errors.New("file already exists")
+	ErrNotExist   = errors.New("file does not exist")
+)
+
 // PathError records an error and the operation and file path that caused it.
 type PathError struct {
 	Op   string
@@ -12,3 +24,21 @@ type PathError struct {
 }
 
 func (e *PathError) Error() string { return e.Op + " " + e.Path + ": " + e.Err.Error() }
+
+// SyscallError records an error from a specific system call.
+type SyscallError struct {
+	Syscall string
+	Err     error
+}
+
+func (e *SyscallError) Error() string { return e.Syscall + ": " + e.Err.Error() }
+
+// NewSyscallError returns, as an error, a new SyscallError
+// with the given system call name and error details.
+// As a convenience, if err is nil, NewSyscallError returns nil.
+func NewSyscallError(syscall string, err error) error {
+	if err == nil {
+		return nil
+	}
+	return &SyscallError{syscall, err}
+}