[BUILD] Generate include/autoconf.mk from board config files
Use cpp and sed to postprocess config.h and import the defined values
into include/autoconf.mk. autoconf.mk is then included by config.mk to
give 'make' access to the board configuration.
Doing this enables conditional compilation at the Makefile level instead
of by wrapping every .c file with #ifdef/#endif wrappers.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/tools/scripts/define2mk.sed b/tools/scripts/define2mk.sed
new file mode 100644
index 0000000..6464627
--- /dev/null
+++ b/tools/scripts/define2mk.sed
@@ -0,0 +1,29 @@
+#
+# Sed script to parse CPP macros and generate output usable by make
+#
+# It is expected that this script is fed the output of 'gpp -dM'
+# which preprocesses the common.h header files and outputs the final
+# list of CPP macros (and whitespace is sanitized)
+#
+
+# Only process values prefixed with #define CONFIG_
+/^#define CONFIG_[A-Za-z0-9_]\+/ {
+ # Strip the #define prefix
+ s/#define *//;
+ # Change to form CONFIG_*=VALUE
+ s/ \+/=/;
+ # Drop trailing spaces
+ s/ *$//;
+ # drop quotes around string values
+ s/="\(.*\)"$/=\1/;
+ # Concatenate string values
+ s/" *"//g;
+ # Wrap non-numeral values with quotes
+ s/=\(.*\?[^0-9].*\)$/=\"\1\"/;
+ # Change '1' and empty values to "y" (not perfect, but
+ # supports conditional compilation in the makefiles
+ s/=$/=y/;
+ s/=1$/=y/;
+ # print the line
+ p
+}