1 files changed, 9 insertions, 8 deletions

diff --git a/configure.ac b/configure.ac
index 036b62484..606f4ef7e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -24,25 +24,25 @@ AC_PROG_RANLIB
 HAVE_SPECTRE="no"
 AX_CHECK_COMPILE_FLAG(
     [-mindirect-branch=thunk],
-    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS+=" -mindirect-branch=thunk"]
+    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS="$EXTRA_CFLAGS -mindirect-branch=thunk"]
 )
 AX_CHECK_COMPILE_FLAG(
     [-mretpoline],
-    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS+=" -mretpoline"]
+    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS="$EXTRA_CFLAGS -mretpoline"]
 )
 AX_CHECK_COMPILE_FLAG(
     [-fstack-clash-protection],
-    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS+=" -fstack-clash-protection"]
+    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS="$EXTRA_CFLAGS -fstack-clash-protection"]
 )
 AX_CHECK_COMPILE_FLAG(
     [-fstack-protector-strong],
-    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS+=" -fstack-protector-strong"]
+    [HAVE_SPECTRE="yes" && EXTRA_CFLAGS="$EXTRA_CFLAGS -fstack-protector-strong"]
 )
 
 AC_ARG_ENABLE([analyzer],
     AS_HELP_STRING([--enable-analyzer], [enable GCC 10 static analyzer]))
 AS_IF([test "x$enable_analyzer" = "xyes"], [
-        EXTRA_CFLAGS+=" -fanalyzer"
+        EXTRA_CFLAGS="$EXTRA_CFLAGS -fanalyzer"
 ])
 
 HAVE_APPARMOR=""
@@ -50,7 +50,8 @@ AC_ARG_ENABLE([apparmor],
     AS_HELP_STRING([--enable-apparmor], [enable apparmor]))
 AS_IF([test "x$enable_apparmor" = "xyes"], [
         HAVE_APPARMOR="-DHAVE_APPARMOR"
-        PKG_CHECK_MODULES([AA], libapparmor, [EXTRA_CFLAGS+=" $AA_CFLAGS" && EXTRA_LDFLAGS+=" $AA_LIBS"])
+        PKG_CHECK_MODULES([AA], libapparmor,
+            [EXTRA_CFLAGS="$EXTRA_CFLAGS $AA_CFLAGS" && EXTRA_LDFLAGS="$EXTRA_LDFLAGS $AA_LIBS"])
         AC_SUBST(HAVE_APPARMOR)
 ])
 
@@ -59,7 +60,7 @@ AC_ARG_ENABLE([selinux],
     AS_HELP_STRING([--enable-selinux], [SELinux labeling support]))
 AS_IF([test "x$enable_selinux" = "xyes"], [
         HAVE_SELINUX="-DHAVE_SELINUX"
-        EXTRA_LDFLAGS+=" -lselinux "
+        EXTRA_LDFLAGS="$EXTRA_LDFLAGS -lselinux "
         AC_SUBST(HAVE_SELINUX)
 ])
 
@@ -215,7 +216,7 @@ AC_ARG_ENABLE([gcov],
     AS_HELP_STRING([--enable-gcov], [Gcov instrumentation]))
 AS_IF([test "x$enable_gcov" = "xyes"], [
         HAVE_GCOV="--coverage -DHAVE_GCOV "
-        EXTRA_LDFLAGS+=" -lgcov --coverage "
+        EXTRA_LDFLAGS="$EXTRA_LDFLAGS -lgcov --coverage "
         AC_SUBST(HAVE_GCOV)
 ])