Don't use nested parenthesization. This patch was originally
suggested to bug-autoconf by Philippe De Muyter on 2000-05-28,
but somehow it didn't get incorporated then.
s,[\\$`],\\&,g
t clear
: clear
-s,^[ ]*#[ ]*define[ ][ ]*\(\([^ (][^ (]*\)([^)]*)\)[ ]*\(.*\)$,${ac_dA}\2${ac_dB}\1${ac_dC}\3${ac_dD},gp
+s,^[ ]*#[ ]*define[ ][ ]*\([^ (][^ (]*\)\(([^)]*)\)[ ]*\(.*\)$,${ac_dA}\1${ac_dB}\1\2${ac_dC}\3${ac_dD},gp
t end
s,^[ ]*#[ ]*define[ ][ ]*\([^ ][^ ]*\)[ ]*\(.*\)$,${ac_dA}\1${ac_dB}\1${ac_dC}\2${ac_dD},gp
: end]