From: Teemu Ikonen <tpikonen@gmail.com>
Date: Sat, 13 Oct 2018 21:24:58 +0300
Subject: makefile-fix: Prepend CPPFLAGS value to CFLAGS.

---
 Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 023496c..4c213f4 100644
--- a/Makefile
+++ b/Makefile
@@ -588,7 +588,8 @@ endif
 #########################################################
 CC	= gcc
 C++	= g++
-CFLAGS  += -g -O3 -Wall -D_USE_XOPEN_EXTENDED -fno-strict-aliasing
+CPPFLAGS ?=
+CFLAGS  += $(CPPFLAGS) -g -O3 -Wall -D_USE_XOPEN_EXTENDED -fno-strict-aliasing
 LDFLAGS +=
 F90C = gfortran
 F90FLAGS = -g -fno-range-check
