lib: macros - Add ENUM_NEGATE

Handles enumeration flag negation.

diff --git a/src/lib/macros.h b/src/lib/macros.h
index 6a3c7f45b156d09941903b1b06ab5b582f4c0d49..7e67a4d16d271e19fc9935300eef1c699f74267b 100644 (file)
--- a/src/lib/macros.h
+++ b/src/lib/macros.h
@@ -280,3 +280,7 @@
 # define ATTR_NO_SANITIZE_INTEGER
 # define ATTR_NO_SANITIZE_IMPLICIT_CONVERSION
 #endif
+
+/* negate enumeration flags in a way that avoids implicit conversion */
+#define ENUM_NEGATE(x) \
+       ((unsigned int)(~(x)) + COMPILE_ERROR_IF_TRUE(sizeof((x)) > sizeof(int) || (x) < 0 || (x) > INT_MAX))