Visual C: reduce the dependency paths to be relative

use lib '.';

use configdata;

use File::Spec::Functions qw(canonpath rel2abs);

use File::Spec::Functions qw(:DEFAULT rel2abs);

use File::Compare qw(compare_text);

# When using stat() on Windows, we can get it to perform better by avoid some

# Ok, primary checks are done, time to do some real work

my $producer = shift @ARGV;

die "Producer not given\n" unless $producer;

my $abs_srcdir = rel2abs($config{sourcedir});

my $abs_blddir = rel2abs($config{builddir});

my $producer = shift @ARGV;

die "Producer not given\n" unless $producer;

# Convenient cache of absolute to relative map.  We start with filling it

# with mappings for the known generated header files.  They are relative to

# the current working directory, so that's an easy task.

# NOTE: there's more than C header files that are generated.  They will also

# generate entries in this map.  We could of course deal with C header files

# only, but in case we decide to handle more than just C files in the future,

# we already have the mechanism in place here.

# NOTE2: we lower case the index to make it searchable without regard for

# character case.  That could seem dangerous, but as long as we don't have

# files we depend on in the same directory that only differ by character case,

# we're fine.

my %depconv_cache =

    map { lc catfile($abs_blddir, $_) => $_ }

    keys %{$unified_info{generate}};

my %procedures = (

    'gcc' => undef,             # gcc style dependency files needs no mods

                # VC gives us absolute paths for all include files, so to

                # remove system header dependencies, we need to check that

                # they don't match $abs_srcdir or $abs_blddir

                $tail = canonpath($tail);

                if ($tail =~ m|^\Q$abs_srcdir\E|i

                        || $tail =~ m|^\Q$abs_blddir\E|i) {

                    return ($objfile, "\"$tail\"");

                # they don't match $abs_srcdir or $abs_blddir.

                $tail = lc canonpath($tail);

                unless (defined $depconv_cache{$tail}) {

                    my $dep = $tail;

                    # Since we have already pre-populated the cache with

                    # mappings for generated headers, we only need to deal

                    # with the source tree.

                    if ($dep =~ s|^\Q$abs_srcdir\E\\|\$(SRCDIR)\\|i) {

                        $depconv_cache{$tail} = $dep;

                    }

                }

                return ($objfile, '"'.$depconv_cache{$tail}.'"')

                    if defined $depconv_cache{$tail};

                print STDERR "DEBUG[VC]: ignoring $objfile <- $tail\n"

                    if $debug;

            }

            return undef;