From 6d3237a0b4b532b329949bc26abdcbd4b4325c1a Mon Sep 17 00:00:00 2001
From: Eric Blankenhorn <eric@wolfssl.com>
Date: Wed, 20 Jun 2018 09:49:33 -0500
Subject: [PATCH] Add support for C99 tools withoutstrings.h and add option to
 disable C99 checking.

---
 wolfssl/wolfcrypt/types.h   | 4 ++--
 wolfssl/wolfcrypt/wc_port.h | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/wolfssl/wolfcrypt/types.h b/wolfssl/wolfcrypt/types.h
index 3329b794f..7008abb50 100755
--- a/wolfssl/wolfcrypt/types.h
+++ b/wolfssl/wolfcrypt/types.h
@@ -332,8 +332,8 @@
         #elif defined(USE_WINDOWS_API) || defined(FREERTOS_TCP_WINSIM)
 	        #define XSTRNCASECMP(s1,s2,n) _strnicmp((s1),(s2),(n))
         #else
-            #if (defined(HAVE_STRINGS_H) || defined(WOLF_C99)) && \
-                !defined(WOLFSSL_SGX)
+            #if defined(HAVE_STRINGS_H) && defined(WOLF_C99) && \
+                !defined(WOLFSSL_SGX) && !defined(WOLFSSL_ARDUINO)
                 #include <strings.h>
             #endif
 	        #define XSTRNCASECMP(s1,s2,n) strncasecmp((s1),(s2),(n))
diff --git a/wolfssl/wolfcrypt/wc_port.h b/wolfssl/wolfcrypt/wc_port.h
index de4f8d9e5..7490b08de 100644
--- a/wolfssl/wolfcrypt/wc_port.h
+++ b/wolfssl/wolfcrypt/wc_port.h
@@ -33,8 +33,9 @@
     extern "C" {
 #endif
 
-/* detect C99 */
-#if !defined(WOLF_C99) && defined(__STDC_VERSION__)
+/* Detect if compiler supports C99. "NO_WOLF_C99" can be defined in
+ * user_settings.h to disable checking for C99 support. */
+#if !defined(WOLF_C99) && defined(__STDC_VERSION__) && !defined(NO_WOLF_C99)
     #if __STDC_VERSION__ >= 199901L
         #define WOLF_C99
     #endif