misc: add blimits.h

misc/blimits.h

@@ -0,0 +1,53 @@
+/**
+ * @file blimits.h
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * This file is part of BadVPN.
+ * 
+ * BadVPN is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ * 
+ * BadVPN is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef BADVPN_BLIMITS_H
+#define BADVPN_BLIMITS_H
+
+#include <stdint.h>
+
+#define BTYPE_IS_SIGNED(type) ((type)-1 < 0)
+
+#define BSIGNED_TYPE_MIN(type) ( \
+    sizeof(type) == 1 ? INT8_MIN : ( \
+    sizeof(type) == 2 ? INT16_MIN : ( \
+    sizeof(type) == 4 ? INT32_MIN : ( \
+    sizeof(type) == 8 ? INT64_MIN : 0))))
+
+#define BSIGNED_TYPE_MAX(type) ( \
+    sizeof(type) == 1 ? INT8_MAX : ( \
+    sizeof(type) == 2 ? INT16_MAX : ( \
+    sizeof(type) == 4 ? INT32_MAX : ( \
+    sizeof(type) == 8 ? INT64_MAX : 0))))
+
+#define BUNSIGNED_TYPE_MIN(type) ((type)0)
+
+#define BUNSIGNED_TYPE_MAX(type) ( \
+    sizeof(type) == 1 ? UINT8_MAX : ( \
+    sizeof(type) == 2 ? UINT16_MAX : ( \
+    sizeof(type) == 4 ? UINT32_MAX : ( \
+    sizeof(type) == 8 ? UINT64_MAX : 0))))
+
+#define BTYPE_MIN(type) (BTYPE_IS_SIGNED(type) ? BSIGNED_TYPE_MIN(type) : BUNSIGNED_TYPE_MIN(type))
+#define BTYPE_MAX(type) (BTYPE_IS_SIGNED(type) ? BSIGNED_TYPE_MAX(type) : BUNSIGNED_TYPE_MAX(type))
+
+#endif