commit 8d66c92047f7b02dcf7262bc34f06492268554c9
author David Brown <david.brown@linaro.org> Tue Apr 16 15:58:22 2019 -0600
committer David Brown <davidb@davidb.org> Wed Apr 17 05:28:18 2019 +0700
tree 33d91b43e32cbde3656e74ca3f527ca3fcfe3dcd
parent 30f68b854ec5124f9107f95c56d87753ed1f9260

boot: bootutil: Change conditional to valid C

The change

    boot: bootutil: Simplify check for crypto backends to reduce complexity

    Adding multiple crypto backends will grow quadraticly. This change will
    ensure that the growth will be linear and generate less complexity.

unfortunately is not legal C.  It can be fixed by eliminating the
intermediate macro, so that the `defined` keywords are within the `#if`.

Signed-off-by: David Brown <david.brown@linaro.org>

boot/bootutil/include/bootutil/sha256.h

diff --git a/boot/bootutil/include/bootutil/sha256.h b/boot/bootutil/include/bootutil/sha256.h
index e898a06..d266a36 100644
--- a/boot/bootutil/include/bootutil/sha256.h
+++ b/boot/bootutil/include/bootutil/sha256.h
@@ -31,10 +31,9 @@
 
 #include "mcuboot_config/mcuboot_config.h"
 
-#define NUM_CRYPTO_BACKENDS (defined(MCUBOOT_USE_MBED_TLS) +\
-			     defined(MCUBOOT_USE_TINYCRYPT) +\
-			     defined(MCUBOOT_USE_CC310))
-#if NUM_CRYPTO_BACKENDS != 1
+#if (defined(MCUBOOT_USE_MBED_TLS) + \
+     defined(MCUBOOT_USE_TINYCRYPT) + \
+     defined(MCUBOOT_USE_CC310)) != 1
     #error "One crypto backend must be defined either CC310, MBED_TLS or TINYCRYPT"
 #endif