And last (and probably least) is the perl script that pulls the dependency stuff out of Makefile and into .depend.
# Open the Makefile that has been mangled by 'make depend'
# and suck it into a perl array.
open(IF,"<Makefile") || die;
@makefile = <IF>;
close(IF);
# Now open our .depend file and a temporary Makefile.
# We'll split the original Makefile between these two.
open(DF,">.depend") || die;
open(MF,">Makefile.tmp") || die;
# For each line we read out of the original file...
foreach (@makefile) {
# If we're into the dependency section, write the line
# into the .depend file.
#
if( $depend ) {
print DF $_;
}
else {
# If we haven't gotten to the dependency section yet
# then see if the current line is the separator that
# "make depend" causes to be inserted.
#
if( m/^\Q# DO NOT DELETE THIS LINE -- g++dep uses it.\E/ ) {
# If so, change our "mode" and skip this line.
++$depend;
next;
}
# Also skip the "include .depend" that we insert. If we
# don't do this, it is possible to have a bunch of these
# inserted into the output when we read an unmangled Makefile
next if( m/^include .depend/ );
# Print the non-dependency info to the temporary Makefile
print MF $_;
}
}
# Tell our new Makefile to include the
dependency file
print MF "include .depend\n";
# Close the two output files...
close(DF);
close(MF);
# Unlink (remove) the original Makefile
and rename our
# temporary file. There's obviously
room for error checking
# here but we've got the Makefile checked
into some revision
# control system anyway. Don't we?
unlink("Makefile");
rename("Makefile.tmp","Makefile");
exit(0);