From 31f88a29dee0b8ab5d93c34e83d118daf01a7b21 Mon Sep 17 00:00:00 2001
From: Gilles Peskine <Gilles.Peskine@arm.com>
Date: Tue, 14 Apr 2020 19:39:56 +0200
Subject: [PATCH] Strict C99: make sure that fileno() is declared

<stdio.h> only declares the non-ISO-C function fileno() if an
appropriate POSIX symbol is defined or if using a compiler such as GCC
in non-pedantic mode. Define the appropriate POSIX symbol.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
---
 tests/suites/main_test.function | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tests/suites/main_test.function b/tests/suites/main_test.function
index a1ba610585..db1c88a80e 100644
--- a/tests/suites/main_test.function
+++ b/tests/suites/main_test.function
@@ -19,6 +19,12 @@
  *  This file is part of Mbed TLS (https://tls.mbed.org)
  */
 
+#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
+#if !defined(_POSIX_C_SOURCE)
+#define _POSIX_C_SOURCE 1 // for fileno() from <stdio.h>
+#endif
+#endif
+
 #if !defined(MBEDTLS_CONFIG_FILE)
 #include <mbedtls/config.h>
 #else