Fix MBEDTLS_MAYBE_UNUSED for IAR
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/common.h b/library/common.h
index 570b97e..73b3d61 100644
--- a/library/common.h
+++ b/library/common.h
@@ -344,8 +344,11 @@
# define MBEDTLS_MAYBE_UNUSED __attribute__((unused))
#endif
#if !defined(MBEDTLS_MAYBE_UNUSED) && defined(__IAR_SYSTEMS_ICC__) && defined(__VER__)
+/* IAR does support __attribute__((unused)), but only if the -e flag (extended language support)
+ * is given; the pragma always works.
+ * Unfortunately the pragma affects the rest of the file where it is used, but this is harmless. */
# if (__VER__ >= 8010000) // IAR 8.1 or later
-# define MBEDTLS_MAYBE_UNUSED __attribute__((unused))
+# define MBEDTLS_MAYBE_UNUSED _Pragma("diag_suppress=Pe177")
# endif
#endif
#if !defined(MBEDTLS_MAYBE_UNUSED) && defined(_MSC_VER)