build: always use the C compiler to preprocess
We're a bit inconsistent about which tool we use to preprocess source
files; in some places we use `$(CC) -E` whilst in others we use `cpp`.
This change forces all invocations of the C preprocessor to use the
first scheme, which ensures that the preprocessor behaves the same way
as the C compiler used when compiling C source files.
Change-Id: Iede2f25ff86ea8b43d7a523e32648058d5023832
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/plat/rockchip/rk3399/drivers/m0/Makefile b/plat/rockchip/rk3399/drivers/m0/Makefile
index 79e09f0..1763246 100644
--- a/plat/rockchip/rk3399/drivers/m0/Makefile
+++ b/plat/rockchip/rk3399/drivers/m0/Makefile
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2024, Arm Limited and Contributors. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
@@ -40,7 +40,7 @@
# Cross tool
CC := ${M0_CROSS_COMPILE}gcc
-CPP := ${M0_CROSS_COMPILE}cpp
+CPP := ${M0_CROSS_COMPILE}gcc -E
AR := ${M0_CROSS_COMPILE}ar
OC := ${M0_CROSS_COMPILE}objcopy
OD := ${M0_CROSS_COMPILE}objdump