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lib/Makefile/Update/Makefile.pm  view on Meta::CPAN

package Makefile::Update::Makefile;
# ABSTRACT: Update lists of files in makefile variables.

use Exporter qw(import);
our @EXPORT = qw(update_makefile);

use strict;
use warnings;

our $VERSION = '0.4'; # VERSION



sub update_makefile
{
    my ($in, $out, $vars) = @_;

    # Variable whose contents is being currently replaced and its original
    # name in the makefile.
    my ($var, $makevar);

    # Hash with files defined for the specified variable as keys and 0 or 1
    # depending on whether we have seen them in the input file as values.
    my %files;

    # Array of lines in the existing makefile.
    my @values;

    # True if the values are in alphabetical order: we use this to add new
    # entries in alphabetical order too if the existing ones use it, otherwise
    # we just append them at the end.
    my $sorted = 1;

    # Extensions of the files in the files list (they're keys of this hash,
    # the values are not used), there can be more than one (e.g. ".c" and
    # ".cpp").
    my %src_exts;

    # Extension of the files in the makefiles: here there can also be more
    # than one, but in this case we just give up and don't perform any
    # extensions translation because we don't have enough information to do it
    # (e.g. which extension should be used for the new files in the makefile?).
    # Such case is indicated by make_ext being empty (as opposed to its
    # initial undefined value).
    my $make_ext;

    # Helper to get the extension. Note that the "extension" may be a make
    # variable, e.g. the file could be something like "foo.$(obj)", so don't
    # restrict it to just word characters.
    sub _get_ext { $_[0] =~ /(\.\S+)$/ ? $1 : undef }

    # Indent and the part after the value (typically some amount of spaces and
    # a backslash) for normal lines and, separately, for the last one, as it
    # may or not have backslash after it.
    my ($indent, $tail, $last_tail);

    # We can't use the usual check for EOF inside while itself because this
    # wouldn't work for files with no new line after the last line, so check
    # for the EOF manually.
    my $eof = 0;

    # Set to 1 if we made any changes.
    my $changed = 0;
    while (1) {
        my $line = <$in>;
        if (defined $line) {
            chomp $line;
        } else {
            $line = '';
            $eof = 1;
        }

        # If we're inside the variable definition, parse the current line as
        # another file name,