configure: change CONFIG_ to use macros.

Makes the variables accessible in CPP.

2 files changed, 3 insertions, 3 deletions

diff --git a/README.md b/README.md
index 017eb73..05a45fa 100644
--- a/README.md
+++ b/README.md
@@ -84,7 +84,7 @@ $ make DESTDIR="" install
 The configure script takes three forms of arguments.
 
 1) Long-opts:           `--prefix=/usr`, `--help`
-2) Variables:           `CC=/bin/cc`, `CFLAGS="-O3"`, `CONFIG_TINY=1`, `LDFLAGS=" "`
+2) Variables:           `CC=/bin/cc`, `CFLAGS="-O3"`, `LDFLAGS=" "`
 3) C macro definitions: `-DMACRO`, `-DMACRO=VALUE`, `-UMACRO`
 
 There are three different build configurations.
@@ -106,7 +106,7 @@ Bonus example:
 ```sh
 ./configure \
   --prefix=/usr \
-  CONFIG_TINY=1 \
+  -DCONFIG_TINY=1 \
   CC=clang \
   CFLAGS="$CFLAGS -flto -static" \
   -DDFM_NO_COLOR \
diff --git a/configure b/configure
index 7d8079b..90710c6 100755
--- a/configure
+++ b/configure
@@ -83,7 +83,7 @@ case ${DPP_LEVEL:-} in '')
   for a do case $a in
     --help) cat "$0"; exit 0 ;;
        -D*) mo="${mo:-}$a
-" _a=${a#-D}; export "${_a%%=*}="  ;;
+" _a=${a#-D}; export "${_a%%=*}=1"  ;;
        -U*) cc_flags="$cc_flags $a"; unset  "${a#-U}" ;;
      *?=?*) export "${a#--}" ;;
   esac done