Use "#pragma once" as include guard

While "#pragma once" is not part of the C or C++ standards, it is a construct
supported "by the vast majority of modern compilers"[1]. The previously used
include guards starting with two underscores were also in violation of the
relevant standards: identifiers starting with a double underscore ("__") are
reserved for the implementation[2].

[1] https://en.cppreference.com/w/cpp/preprocessor/impl#.23pragma_once
[2] https://eel.is/c++draft/lex.name#3.1

Signed-off-by: Michael Hanselmann <public@hansmi.ch>

6 files changed, 6 insertions, 25 deletions

diff --git a/usbredirhost/usbredirhost.h b/usbredirhost/usbredirhost.h
index bd30e16..9e13610 100644
--- a/usbredirhost/usbredirhost.h
+++ b/usbredirhost/usbredirhost.h
@@ -18,8 +18,7 @@
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
-#ifndef __USBREDIRHOST_H
-#define __USBREDIRHOST_H
+#pragma once
 
 #include <libusb.h>
 #include "usbredirparser.h"
@@ -182,5 +181,3 @@ int usbredirhost_check_device_filter(const struct usbredirfilter_rule *rules,
 #ifdef __cplusplus
 }
 #endif
-
-#endif
diff --git a/usbredirparser/strtok_r.h b/usbredirparser/strtok_r.h
index 50e6e0e..fd08c15 100644
--- a/usbredirparser/strtok_r.h
+++ b/usbredirparser/strtok_r.h
@@ -16,11 +16,7 @@
    License along with the GNU C Library; if not, write to the Free
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
-
-#ifndef _USBREDIRPARSER_STRTOK_H_
-#define _USBREDIRPARSER_STRTOK_H_
+#pragma once
 
 char *
 glibc_strtok_r(char *s, const char *delim, char **save_ptr);
-
-#endif
diff --git a/usbredirparser/usbredirfilter.h b/usbredirparser/usbredirfilter.h
index eed4b51..eb015bf 100644
--- a/usbredirparser/usbredirfilter.h
+++ b/usbredirparser/usbredirfilter.h
@@ -18,8 +18,7 @@
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
-#ifndef __USBREDIRFILTER_H
-#define __USBREDIRFILTER_H
+#pragma once
 
 #include <stdio.h>
 #include <stdint.h>
@@ -139,5 +138,3 @@ void usbredirfilter_free(void *ptr);
 #ifdef __cplusplus
 }
 #endif
-
-#endif
diff --git a/usbredirparser/usbredirparser.h b/usbredirparser/usbredirparser.h
index 426b6d6..db0bc35 100644
--- a/usbredirparser/usbredirparser.h
+++ b/usbredirparser/usbredirparser.h
@@ -18,8 +18,7 @@
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
-#ifndef __USBREDIRPARSER_H
-#define __USBREDIRPARSER_H
+#pragma once
 
 #include "usbredirproto.h"
 
@@ -382,5 +381,3 @@ int usbredirparser_unserialize(struct usbredirparser *parser_pub,
 #ifdef __cplusplus
 }
 #endif
-
-#endif
diff --git a/usbredirparser/usbredirproto-compat.h b/usbredirparser/usbredirproto-compat.h
index 9155d45..312abe8 100644
--- a/usbredirparser/usbredirproto-compat.h
+++ b/usbredirparser/usbredirproto-compat.h
@@ -18,8 +18,7 @@
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
-#ifndef __USBREDIRPROTO_COMPAT_H
-#define __USBREDIRPROTO_COMPAT_H
+#pragma once
 
 /* PACK macros borrowed from spice-protocol */
 #ifdef __GNUC__
@@ -82,5 +81,3 @@ struct usb_redir_bulk_packet_header_16bit_length {
 #if defined(__MINGW32__) || !defined(__GNUC__)
 #pragma pack(pop)
 #endif
-
-#endif
diff --git a/usbredirparser/usbredirproto.h b/usbredirparser/usbredirproto.h
index d1d51a4..667ffce 100644
--- a/usbredirparser/usbredirproto.h
+++ b/usbredirparser/usbredirproto.h
@@ -18,8 +18,7 @@
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
-#ifndef __USBREDIRPROTO_H
-#define __USBREDIRPROTO_H
+#pragma once
 
 /* PACK macros borrowed from spice-protocol */
 #ifdef __GNUC__
@@ -303,5 +302,3 @@ struct usb_redir_buffered_bulk_packet_header {
 #ifdef __cplusplus
 }
 #endif
-
-#endif