tmpasm: How to print includes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Some tree nodes have a list of #include directives that need to be
reproduced in the C source for proper operation. The saprator on this list
is a "\" followed by an "n". For exampe:

/target/libs/socket/getnameinfo/includes=#include <sys/types.h>\n#include <sys/socket.h>\n\n#include <netdb.h>\n

The 

---- example template start ----

# Make a copy to a temp var so the original input doesn't need to be changed
# (so that the cache is not modified)
put /tmpasm/tmp  /target/libs/socket/getnameinfo/includes


# replace all "\n" with a real newline in the temp var
gsub /tmpasm/tmp {[\\]n} {\n}

# make sure each #include is there only once and remove empty lines, but keep
# order of #includes (by first appearance). Setting IFS to newline because the
# default IFS "any whitespace".
#
# Note: IFS is a list of characters, not a regex; \n in {} string is
# replaced while template parsing
#
put /tmpasm/IFS {\n}
uniq /tmpasm/tmp

# print the result
print /tmpasm/tmp

---- example template end ----