Index: driver/Makefile.am
===================================================================
--- driver/Makefile.am	(revision 0c1b5660b6f5a0957c905780ecc5883a812e52a7)
+++ driver/Makefile.am	(revision 47c1928b39e141cf752717688b57df8b99a499d7)
@@ -18,5 +18,5 @@
 
 # applies to both programs
-AM_CXXFLAGS = -Wall -O2 -g -std=c++14 -I${abs_top_srcdir}/src
+AM_CXXFLAGS = @HOST_FLAGS@ -Wall -O2 -g -std=c++14 -I${abs_top_srcdir}/src
 
 # don't install cfa directly
Index: driver/Makefile.in
===================================================================
--- driver/Makefile.in	(revision 0c1b5660b6f5a0957c905780ecc5883a812e52a7)
+++ driver/Makefile.in	(revision 47c1928b39e141cf752717688b57df8b99a499d7)
@@ -213,4 +213,5 @@
 EXEEXT = @EXEEXT@
 GREP = @GREP@
+HOST_FLAGS = @HOST_FLAGS@
 INSTALL = @INSTALL@
 INSTALL_DATA = @INSTALL_DATA@
@@ -301,5 +302,5 @@
 
 # applies to both programs
-AM_CXXFLAGS = -Wall -O2 -g -std=c++14 -I${abs_top_srcdir}/src
+AM_CXXFLAGS = @HOST_FLAGS@ -Wall -O2 -g -std=c++14 -I${abs_top_srcdir}/src
 cfa_SOURCES = cfa.cc