[BusyBox] config.h/bb_config.h translation broken

[Paul Fox]

my busybox build is broken by commit r10944, for
ENABLE_FEATURE_XXX support.

the problem is the sed, running in this Makefile target:

include/bb_config.h: include/config.h
        echo "#ifndef AUTOCONF_INCLUDED" > $@
        sed -e 's/#undef CONFIG_\(.*\)/#define ENABLE_\1 0/' \ 
            -e 's/#define CONFIG_\(.*\)/#define CONFIG_\1\n#define ENABLE_\1/' \
                < $< >> $@
        echo "#endif" >> $@


sed on my development machine (GNU sed version 3.02 -- old, okay)
expands the "\n" in the replacement half of the second line to
the character 'n', rather than to a newline, and i get this kind
of thing:
#define CONFIG_FEATURE_ROTATE_LOGFILE 1n#define ENABLE_FEATURE_ROTATE_LOGFILE 1
rather than
#define CONFIG_FEATURE_ROTATE_LOGFILE 1
#define ENABLE_FEATURE_ROTATE_LOGFILE 1

i think inserting newlines with sed can be hard to do
portably, this two-pass approach works:

include/bb_config.h: include/config.h
        echo "#ifndef AUTOCONF_INCLUDED" > $@
        sed -e 's/#undef CONFIG_\(.*\)/#define ENABLE_\1 0/' < $< >> $@
        sed -n -e 's/#define CONFIG_/#define ENABLE_/p' < $< >> $@
        echo "#endif" >> $@

but all of the "ENABLE_XXX 1" lines end up at the bottom of the file.

i won't commit this -- someone probably has a better idea.

paul
=---------------------
 paul fox, pgf at brightstareng.com